Speed ​​Shifter

Abstract

The speed change device (21) has an input shaft (22), an output shaft (23), a planetary gear mechanism (29), a first transmission (33), a second transmission (34) and a controller (25). The planetary gear mechanism (29) includes a planetary gear carrier (29A) connected to the input shaft (22), a first sun gear (29B) connected to the first transmission (33), and a second sun gear (29C) connected to the output shaft (23). The second transmission (34) transmits the power transmitted from the first transmission (33) to the output shaft (23), or transmits the power transmitted from the output shaft (23) to the first transmission (33). The controller (25) changes the rotation speed of the output shaft (23) relative to the rotation speed of the input shaft (22) by changing the rotation speed of the first transmission (33).

Description

Technical Field

[0001] The present invention relates to a transmission device mounted on a vehicle such as a wheel loader or a hydraulic excavator. Background Art

[0002] For example, Patent Document 1 describes a construction machine that transmits power by using a planetary continuously variable transmission mechanism composed of a planetary gear mechanism and an electric motor. According to the construction machine of Patent Document 1, by using a planetary continuously variable transmission mechanism, it is possible to reduce the sudden change in the rotation speed of the engine and suppress the sudden change in the movement speed of the loading and unloading machine.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2008-247269 (Japanese Patent No. 5095252) Summary of the invention

[0006] However, the technology described in Patent Document 1 may not be able to effectively use the speed range of the planetary continuously variable transmission mechanism.

[0007] An object of one embodiment of the present invention is to provide a transmission device capable of effectively utilizing the speed-increasing range of a planetary continuously variable transmission mechanism.

[0008] A continuously variable transmission device according to one embodiment of the present invention comprises: an input shaft connected to a power source; an output shaft connected to a load; a planetary mechanism provided between the input shaft and the output shaft; a first transmission connected to the planetary mechanism; a second transmission provided separately for the first transmission; and a controller for changing the rotation speed of the first transmission, wherein the planetary mechanism comprises the following three components: a planetary gear carrier, a first sun gear component rotating about a rotation center axis of the planetary gear carrier, and a second sun gear component rotating about a rotation center axis of the planetary gear carrier, the first component being one of the three components of the planetary mechanism being directly connected to the input shaft or via other components, the second component other than the first component of the three components of the planetary mechanism being directly connected to the first transmission or via other components, and the second component other than the first component of the three components of the planetary mechanism being directly connected to the first transmission or via other components, A third component other than the second component is connected to the output shaft directly or via other components. The planetary gear carrier of the planetary mechanism supports a planetary component and a balance component that rotate together with the first sun gear component and the second sun gear component while revolving around the rotation center axis of the planetary gear carrier and transmitting power. The planetary mechanism distributes the torque transmitted from the power source to the planetary mechanism to the second component and the third component. The planetary mechanism performs a two-degree-of-freedom rotational motion between the first component, the second component and the third component. The second transmission transmits the power transmitted from the first transmission to the load or the power source, or transmits the power transmitted from the load or the power source to the first transmission. The controller changes the rotation speed of the output shaft relative to the rotation speed of the input shaft by changing the rotation speed of the first transmission.

[0009] In addition, a continuously variable transmission device according to an embodiment of the present invention includes: an input shaft connected to a power source; an output shaft connected to a load; a planetary mechanism provided between the input shaft and the output shaft; a first transmission connected to the planetary mechanism; a second transmission provided separately from the first transmission; and a controller for changing the rotation speed of the first transmission, wherein the planetary mechanism is configured to include the following three components: a planetary gear carrier, a sun gear member rotating about a rotation center axis of the planetary gear carrier, and an annular member located radially outward from the sun gear member and rotating about the rotation center axis of the planetary gear carrier, wherein a first component as one of the three components of the planetary mechanism is connected to the input shaft directly or via another component, a second component other than the first component of the three components of the planetary mechanism is connected to the first transmission directly or via another component, and a third component other than the first component and the second component of the three components of the planetary mechanism is connected to the output shaft directly or via another component, and a sun gear member, one side of which revolves around the rotation center axis of the planetary gear carrier, is supported on the planetary gear carrier of the planetary mechanism. a planetary member that transmits power while rotating together with the sun gear member and the annular member, the planetary mechanism distributes the torque transmitted from the power source to the planetary mechanism to the second member and the third member, the planetary mechanism performs a two-degree-of-freedom rotational motion between the first member, the second member and the third member, the second transmission transmits the power transmitted from the first transmission to the load or the power source, or transmits the power transmitted from the load or the power source to the first transmission, the controller changes the rotation speed of the output shaft relative to the rotation speed of the input shaft by changing the rotation speed of the first transmission, and, when a power transmission path that transmits power from the power source to the load through the planetary mechanism is set as a first power transmission path, a second power transmission path is provided in parallel with the first power transmission path and transmits power to the load through meshing of gears without passing through the planetary mechanism, the second power transmission path has a first clutch that switches between engagement and release, and the controller connects the first clutch to transmit power through the second power transmission path.

[0010] According to one embodiment of the present invention, the speed range of the planetary continuously variable transmission mechanism including the planetary mechanism, the first transmission and the second transmission can be effectively used. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a left side view showing the wheel loader equipped with the transmission device according to the first embodiment.

[0012] Figure 2 Yes means Figure 1 A partially cutaway side view of a speed change device in FIG.

[0013] Figure 3 It is a diagram showing the configuration of the transmission according to the first embodiment.

[0014] Figure 4 Yes Figure 3 A diagram showing the speed change device and the interior of the planetary mechanism.

[0015] Figure 5 yes Figure 4 An enlarged view of part (V) in FIG.

[0016] Figure 6 Observed from the power source side Figure 4 Illustration of the planetary mechanism in .

[0017] Figure 7 Yes means Figure 4 Characteristic line diagram showing the relationship between the rotation speeds of the various components of the planetary mechanism (“No1-A” in Table 4 described later).

[0018] Figure 8 This is a characteristic diagram showing the relationship between the rotational speeds of the various components of the planetary mechanism of "No. 1-C" in Table 4 described later.

[0019] Fig. 9 This is a characteristic diagram showing the relationship between the rotational speeds of the various components of the planetary mechanism of "No. 1-B" in Table 4 described later.

[0020] Fig.10 yes Figure 4 An enlarged view of the (X) portion in FIG.

[0021] Fig.11 This is a driving force diagram showing the ideal relationship between vehicle speed and traction of a wheel loader.

[0022] Fig.12 This is a driving force diagram showing the relationship between the vehicle speed and the traction force of the wheel loader according to the first embodiment.

[0023] Fig.13 The first modification (structure without external locking) is shown in FIG. Figure 3 Same composition diagram.

[0024] Fig.14 The second modification (internal locking by braking) is shown in FIG. Figure 3 Same composition diagram.

[0025] Fig.15 The third modification (internal locking by braking and no inertial element) and Figure 3 Same composition diagram.

[0026] Fig.16 This is a driving force diagram showing the relationship between the vehicle speed and traction force of a wheel loader equipped with a transmission without external lock.

[0027] Fig.17 This is a driving force diagram showing the relationship between the vehicle speed and traction force of a wheel loader equipped with a transmission without an internal lock.

[0028] Fig.18 The fourth modification (the configuration in which the input shaft is connected to the first sun gear member and the first transmission is connected to the planetary gear carrier) is shown in FIG. Figure 4 Same composition diagram.

[0029] Fig.19 The fifth modification (the configuration in which the input shaft is connected to the first sun gear member and the first transmission is connected to the second sun gear member) is shown in FIG. Figure 4 Same composition diagram.

[0030] Fig. 20 The sixth modification (the second transmission is connected to the output shaft) is shown in FIG. Figure 4 Same composition diagram.

[0031] Fig.21 This is a diagram showing the second embodiment. Figure 4 Same composition diagram.

[0032] Fig. 22 yes Fig.21 An enlarged view of part (XXII) in FIG.

[0033] Fig.23 Observed from the power source side Fig.21 Illustration of the planetary mechanism in .

[0034] Fig.24 Yes means Fig.21 Characteristic line diagram of the relationship between the rotation speeds of the three components of the planetary mechanism.

[0035] Fig.25 The seventh modification (the input shaft is connected to the annular member and the first transmission is connected to the planetary carrier) is shown in FIG. Fig.21 Same composition diagram.

[0036] Fig.26 The eighth modification (the input shaft is connected to the planetary gear carrier and the first transmission is connected to the ring member) is shown in FIG. Fig.21 Same composition diagram.

[0037] Fig. 27The ninth modification (the input shaft is connected to the annular member and the first transmission is connected to the sun gear member) is shown in FIG. Fig.21 Same composition diagram.

[0038] Fig.28 The 10th modification (the input shaft is connected to the sun gear member and the first transmission is connected to the ring member) is shown in FIG. Fig.21 Same composition diagram.

[0039] Fig.29 The eleventh modified example (the input shaft is connected to the sun gear member and the first transmission is connected to the planetary gear carrier) is shown in FIG. Fig.21 Same composition diagram.

[0040] Fig.30 The 12th modification (the second transmission is connected to the input shaft) is shown in FIG. Figure 3 Same composition diagram.

[0041] Fig.31 The 13th modification (the second transmission is connected to the third connecting member connected to the inert element) is shown in FIG. Figure 3 Same composition diagram.

[0042] Fig.32 The fourteenth modification (the second transmission is connected to the odd-numbered gears of the multi-speed transmission mechanism) is shown in FIG. Figure 3 Same composition diagram.

[0043] Fig.33 The fifteenth modification (the second transmission is connected to the first forward speed gear of the multi-speed transmission mechanism) is shown in FIG. Figure 3 Same composition diagram.

[0044] Fig.34 The sixteenth modification (the second transmission is connected to the forward three-speed gear of the multi-speed transmission mechanism) is shown in FIG. Figure 3 Same composition diagram.

[0045] Fig.35 The seventeenth modification (the second transmission is connected to the forward second speed gear of the multi-speed transmission mechanism) is shown in FIG. Figure 3 Same composition diagram.

[0046] Fig.36 The 18th modification (the second transmission is connected to the forward 4-speed gear of the multi-speed transmission mechanism) is shown in FIG. Figure 3 Same composition diagram.

[0047] Fig.37 The 19th modification (the second transmission is connected to the reverse first speed gear of the multi-speed transmission mechanism) is shown in FIG. Figure 3 Same composition diagram.

[0048] Fig.38 The 20th modification (the second transmission is connected to the output shaft) is shown in FIG. Figure 3 Same composition diagram.

[0049] Fig.39 The 21st modification (the second transmission is connected to the load side more than the output shaft of the transmission) is shown in FIG. Figure 3 Same composition diagram. DETAILED DESCRIPTION

[0050] Hereinafter, a transmission (gearbox) according to an embodiment will be described in detail with reference to the drawings, taking a case where the transmission is applied to a wheel loader as an example.

[0051] Figures 1 to 12 A first embodiment is shown. Figure 1 In the figure, the wheel loader 1 is a representative example of a vehicle (work vehicle). The wheel loader 1 is constructed as an articulated work vehicle in which a front body 3 provided with left and right front wheels 2 and a rear body 5 provided with left and right rear wheels 4 are connected so as to bend in the left and right directions. That is, the front body 3 and the rear body 5 constitute the body of the wheel loader 1. A central hinge 6 and a steering hydraulic cylinder (not shown) are provided between the front body 3 and the rear body 5. The front body 3 and the rear body 5 are bent in the left and right directions around the central hinge 6 by extending or shortening the steering hydraulic cylinder. As a result, the wheel loader 1 can be steered while traveling.

[0052] A loading and unloading machine 7, also referred to as a working device, is provided on the front body 3 of the wheel loader 1 so as to be capable of pitching and lowering movements. The loading and unloading machine 7 has a loading bucket 7A. On the other hand, a cabin 8 having a cab inside, an engine 9, a hydraulic pump 10, a speed change device 21 as a gearbox (power transmission device), and the like are provided on the rear body 5 of the wheel loader 1. The engine 9 is a power source (prime mover) of the wheel loader 1. In addition to being constituted by a single engine 9 that is not an internal combustion engine, the power source may be constituted by, for example, an engine and an electric motor, or a single electric motor. The hydraulic pump 10 is connected to the engine 9. The hydraulic pump 10 is a hydraulic source for actuating the loading and unloading machine 7. As described later Figure 3 As shown in FIGS. 1 and 10 , the hydraulic pump 10 is connected to the engine 9 via gears 10A and 10B.

[0053] A front axle 12 extending in the left and right directions is provided at the lower side of the front vehicle body 3. Left and right front wheels 2 are provided at both ends of the front axle 12. On the other hand, a rear axle 13 extending in the left and right directions is provided at the lower side of the rear vehicle body 5. Left and right rear wheels 4 are mounted at both ends of the rear axle 13.

[0054] The front axle 12 is connected to the transmission 21 via the front propeller shaft 14. The rear axle 13 is connected to the transmission 21 via the rear propeller shaft 15. The transmission 21 accelerates and decelerates the rotation of the engine 9 and transmits it to the front propeller shaft 14 and the rear propeller shaft 15. That is, the power from the engine 9 is transmitted to the transmission 21 coupled to the engine 9.

[0055] The power from the engine 9 is transmitted from the front and rear output shafts 23A and 23B of the transmission 21 to the front axle 12 and the rear axle 13 via the front propeller shaft 14 and the rear propeller shaft 15 after the speed and rotation direction are adjusted by the transmission 21. Figure 2 As shown, the transmission 21 has an input shaft 22 connected to the engine 9, a front output shaft 23A connected to the front propeller shaft 14, and a rear output shaft 23B connected to the rear propeller shaft 15. The transmission 21 changes speed and switches forward or reverse between the input shaft 22 and the output shafts 23A and 23B by switching the power transmission path in the transmission 21.

[0056] Next, the operation of the wheel loader 1 will be described. The wheel loader 1 repeatedly executes a V-type cycle mainly based on the dump truck loading operation, and an operation mode called load and carry in which the material is directly put into a hopper or the like. The V-type cycle is an operation mode in which soil and sand are excavated after starting and loaded onto a dump truck. The carry mode is an operation mode in which soil and sand are excavated after starting, and transported (high-load travel), and soil is discharged into a dump truck and returned (low-load travel). In order to obtain the optimal travel speed and driving force for various operation states such as starting, excavating, transporting, loading, and returning, the wheel loader 1 needs to frequently switch the transmission 21.

[0057] When digging and starting, the transmission 21 is required to have high traction. Therefore, the transmission 21 needs to increase the reduction ratio to increase the output torque of the output shafts 23A and 23B. Moreover, even if the vehicle speed of the wheel loader 1 is 0 km / h (the rotation speed of the output shafts 23A and 23B is 0), the rotation speed of the input shaft 22 needs to be maintained above a prescribed value so that the engine 9 as a power source does not stop, and the transmission 21 needs to have an infinite speed ratio. In addition, the vehicle speed of the wheel loader 1 during digging is, for example, 0 to 4 km / h.

[0058] When transporting, the transmission 21 needs to transmit power from the input shaft 22 to the output shafts 23A and 23B with high transmission efficiency in order to save fuel consumption. The vehicle speed during transport is, for example, 0 to 13 km / h. On the other hand, in the case of discharging soil to a dump truck, the wheel loader 1 raises the loading and unloading machine 7 while transporting. Therefore, if the rising speed of the loading and unloading machine 7 suddenly slows down, there is a possibility that the loading and unloading machine 7 collides with the dump truck. Therefore, when approaching the dump truck, it is desired to suppress the drastic change in the discharge flow of the hydraulic pump 10. And, for this purpose, it is necessary to control the transmission 21 in a manner that does not cause the rotation speed of the engine 9 to change suddenly. When discharging soil to a dump truck, the vehicle speed for approaching the dump truck is, for example, 0 to 7 km / h. At this vehicle speed, it is desired to suppress the drastic rotation speed change of the engine 9.

[0059] When the vehicle is transported back on a normal road or at a work site without a load, the transmission device 21 needs to transmit power from the input shaft 22 to the output shafts 23A and 23B with high transmission efficiency in order to save fuel. The vehicle speed during the transport is, for example, 0 to 40 km / h. When transporting back, high operability of the loading and unloading machine 7 is not required. Therefore, a sudden change in the rotation speed of the engine 9 can be allowed. However, in order to save fuel, it is necessary to transmit power from the input shaft 22 to the output shafts 23A and 23B with a higher transmission efficiency than when transporting.

[0060] Fig.11 : This is a diagram showing an ideal driving force line of the wheel loader 1 . Fig.11 In the figure, there is an ideal driving force line Lf in the forward direction and an ideal driving force line Lr in the backward direction (backward direction). When moving forward, high traction is required when digging, and high vehicle speed (0 to 40 km / h) is required when transporting back. In addition, the wheel loader 1 needs to stably climb uphill on uphill roads with various slopes located in quarries, etc. Therefore, for example, when the speed is above 3 km / h, it is desired to have a traction force equal to the horsepower regardless of the vehicle speed.

[0061] Fig.11 The range A in φ represents a range in which a high traction force is required for excavation, that is, a range A of the driving force line during excavation. Fig.11 The range B in φ represents a range in which a traction force of equal horsepower is required regardless of the vehicle speed, that is, a range B of a driving force line of equal horsepower in the forward direction. Fig.11 In the range C, the range of the driving force line of equal horsepower is required regardless of the vehicle speed, that is, the range C of the driving force line of equal horsepower in the backward direction. The range B of the driving force line of equal horsepower in the forward direction and the range C of the driving force line of equal horsepower in the backward direction satisfy the following formula 1.

[0062] [Formula 1]

[0063] Traction force [N] × vehicle speed [km / h] × (5 / 18) = fixed

[0064] Furthermore, the wheel loader 1 does not perform excavation in the backward direction. Therefore, the maximum traction force of the ideal driving force line Lr in the backward direction is lower than that in the forward direction.

[0065] However, the transmission 21 used for working vehicles such as the wheel loader 1 is preferably capable of switching between power transmission based on a continuously variable transmission mechanism and power transmission based on a locking mechanism. In this case, the transmission 21 can effectively use the speed range of the continuously variable transmission mechanism. On this basis, it is preferred that the change in acceleration and deceleration of the vehicle can be reduced when switching from power transmission based on a continuously variable transmission mechanism to power transmission based on a locking mechanism. In addition, when the upper limit value of the rotational speed of the transmission and the upper limit value of the torque that can be generated (absorbed) are limited, an arrangement (gear arrangement) in which the speed ratio (gear ratio) of the planetary mechanism (planetary gear mechanism) is an optimal value can be provided, which can improve the transmission efficiency of the continuously variable transmission mechanism.

[0066] Therefore, if Figure 3 as well as Figure 4 As shown, the speed change device 21 of the first embodiment has a mode of transmitting power while continuously changing the speed of the planetary continuously variable transmission mechanism 24, a mode of transmitting power by locking the planetary continuously variable transmission mechanism 24 internally, and a mode of transmitting power by an external locking mechanism (direct coupling mechanism 27) not passing through the planetary gear mechanism 29. The power transmission based on the internal locking is performed by stopping the rotation of the rotating member (e.g., the first sun gear) connected to the first transmission 33 among the three rotating members (e.g., the planetary gear carrier, the first sun gear, and the second sun gear) of the planetary gear mechanism 29. As a result, the speed change range of the planetary continuously variable transmission mechanism 24 can be effectively used.

[0067] On the other hand, the power transmission based on external locking is performed via an external locking mechanism (direct coupling mechanism 27) installed on the outside of the planetary continuously variable transmission mechanism 24. In this case, the power transmission based on external locking is performed in a state where the power transmission based on the planetary continuously variable transmission mechanism 24 is stopped. The stop is performed by releasing (or reducing the torque of) the rotating component (e.g., the first sun gear) connected to the first transmission 33 among the three rotating components (e.g., the planetary gear carrier, the first sun gear, and the second sun gear) of the planetary gear mechanism 29. As a result, power can be transmitted with high transmission efficiency through internal locking, and power transmission can be performed by further increasing the speed within the speed range of the planetary continuously variable transmission mechanism 24.

[0068] Furthermore, according to the first embodiment, Figures 4 to 6As shown, the planetary gear mechanism 29 includes: two sun gears 29B and 29C; a central axis S ( Figure 6 ) as the center and a planetary gear carrier 29A that rotatably supports the planetary gears 29D and the balance gear 29E and rotates around the center axis S of the two sun gears 29B and 29C. As a result, the planetary gear mechanism 29 can be set to a gear arrangement with an optimal gear ratio. That is, by using the planetary gear mechanism 29 with this arrangement, even when using a cheap and small first transmission 33 with limited upper limits of the rotation speed and the upper limit of the torque that can be generated (absorbed) is used, the transmission efficiency of the planetary continuously variable transmission mechanism 24 can be improved.

[0069] The transmission 21 of the first embodiment will be described in detail below. Figure 3 In the figure, the planetary gear mechanism 29 of the transmission 21 is represented by a box, and in contrast, Figure 4 , the interior of the planetary gear mechanism 29, that is, the specific gear arrangement of the planetary gear mechanism 29 is shown. Figure 3 as well as Figure 4 In order to avoid complicating the drawings, the output shaft 23 of the transmission 21 is simply shown as a common output shaft 23 (= output shafts 23A, 23B) that transmits power to both the front shaft 12 and the rear shaft 13. That is, Figure 3 as well as Figure 4 In the figure, a configuration for distributing power to the front output shaft 23A and the rear output shaft 23B via, for example, a center differential mechanism is omitted.

[0070] Figure 3 as well as Figure 4 1 is a mechanism diagram of a transmission 21 of the first embodiment, more specifically, a mechanism diagram of a transmission 21 having both internal locking and external locking. The transmission 21 has an input shaft 22 as an input member, an output shaft 23 as an output member, a planetary continuously variable transmission mechanism 24 as a continuously variable transmission mechanism (main transmission mechanism), and a controller 25. In addition, it is more preferred that the transmission 21 has a multi-speed transmission mechanism 26 as a stepped transmission mechanism (auxiliary transmission mechanism), and a direct coupling mechanism 27 as an external locking mechanism. The direct coupling mechanism 27 has a first clutch 27C connected when power is transmitted through the direct coupling mechanism 27. In addition, the transmission 21 has an inert element 28 (idle shaft 28A, idler gear 28B) that mechanically connects the planetary continuously variable transmission mechanism 24, the multi-speed transmission mechanism 26, and the direct coupling mechanism 27. The planetary continuously variable transmission mechanism 24 constitutes a first power transmission path. The direct coupling mechanism 27 constitutes a second power transmission path.

[0071] The engine 9 is connected to the input shaft 22 of the speed change device 21. The input shaft 22 is provided with a gear 10B for transmitting power to the hydraulic pump 10. In addition, the input shaft 22 is provided with an input gear 27A of the direct coupling mechanism 27. The input shaft 22 is connected to the planetary continuously variable transmission mechanism 24 (more specifically, the planetary gear mechanism 29) via the second connecting member 31 described later. On the other hand, power is output from the output shaft 23 of the speed change device 21. The output shaft 23 of the speed change device 21 also serves as the output shaft 53 of the multi-speed change mechanism 26 described later. The power input from the input shaft 22 is transmitted to the inert element 28 via the planetary continuously variable transmission mechanism 24 or the direct coupling mechanism 27. The power transmitted to the inert element 28 is output from the output shaft 23 through the multi-speed change mechanism 26.

[0072] In addition, the planetary continuously variable transmission mechanism 24 is in an internally locked state by stopping the first connecting member 30 connecting the planetary gear mechanism 29 (for example, the first sun gear 29B) and the first transmission 33. The internally locked state is formed, for example, by stopping the first connecting member 30 by braking the first transmission 33. When the planetary continuously variable transmission mechanism 24 is in an internally locked state, the power input from the input shaft 22 is transmitted to the inertial element 28 through the "second connecting member 31 connecting the planetary gear mechanism 29 (for example, the planetary gear carrier 29A) and the input shaft 22", the "planetary gear mechanism 29", and the "third connecting member 32 connecting the planetary gear mechanism 29 (for example, the second sun gear 29C) and the inertial element 28". Such internal locking will be described later.

[0073] In the first embodiment, the power transmission path for transmitting the power input from the engine 9 to the input shaft 22 to the multi-speed change mechanism 26 can be arbitrarily selected from the following three paths (A), (B), and (C).

[0074] (A) is a continuously variable transmission path (a first power transmission path via the planetary continuously variable transmission mechanism 24) for transmitting the power input from the engine 9 to the input shaft 22 to the multi-speed transmission mechanism 26 while continuously changing the speed of the planetary continuously variable transmission mechanism 24. At this time, the first clutch 27C is released, and the second clutch 36 and the third clutch 37 are connected (coupled).

[0075] (B) is an internal locking path (a first power transmission path via the planetary continuously variable transmission mechanism 24) for transmitting the power input from the engine 9 to the input shaft 22 to the multi-speed transmission mechanism 26 while the planetary continuously variable transmission mechanism 24 is locked internally. At this time, the first clutch 27C is released and the second clutch 36 is connected (coupled). The third clutch 37 is connected (coupled) as needed.

[0076] (C) is an external locking path (a second power transmission path that does not pass through the planetary continuously variable transmission mechanism 24 but passes through the direct coupling mechanism 27) for transmitting the power input from the engine 9 to the input shaft 22 to the multi-speed transmission mechanism 26 via the direct coupling mechanism 27. At this time, the first clutch 27C is connected (coupled), and the second clutch 36 and the third clutch 37 are released as needed.

[0077] Thus, when it is suitable to make the planetary continuously variable transmission mechanism 24 continuously variable, the planetary continuously variable transmission mechanism 24 can be continuously variable to perform power transmission. When it is suitable to lock the inside of the planetary continuously variable transmission mechanism 24, the planetary continuously variable transmission mechanism 24 can be locked to perform power transmission. When it is suitable to perform power transmission via the direct coupling mechanism 27, the power transmission can be performed via the direct coupling mechanism 27.

[0078] The timing suitable for the planetary continuously variable transmission mechanism 24 to continuously change the speed for power transmission is during excavation and transportation and when the vehicle speed is in the range of 0 to 7 km / h. The reasons for this are as follows (a) to (c).

[0079] (a) The transmission efficiency is high when the vehicle is moving and digging.

[0080] (b) The speed ratio can be made infinite. That is, even when the engine 9 is rotating, the torque can be transmitted to the output shaft 23 while stopping the rotation of the output shaft 23. Therefore, it is suitable for excavation work.

[0081] (c) The torque transmitted to the output shaft 23 through the transmission 21 among the power generated by the engine 9 can be controlled. That is, the power can be distributed between the hydraulic pump 10 that operates the loading and unloading machine 7 and the transmission 21.

[0082] The timing suitable for locking the inside of the planetary continuously variable transmission mechanism 24 to transmit power is during transportation and return and when the vehicle speed is in the range of 7 to 9 km / h. The reasons for this are as follows (d) to (e).

[0083] (d) When the vehicle speed increases, the transmission efficiency is higher when the planetary continuously variable transmission mechanism 24 is locked inside to transmit power than when the planetary continuously variable transmission mechanism 24 is continuously variable.

[0084] (e) It is possible to mechanically switch from the continuously variable transmission to the internal lock. Therefore, when switching from the continuously variable transmission to the internal lock, the drastic rotation change of the engine 9 can be suppressed. As a result, the drastic change of the discharge flow of the hydraulic pump 10 can be suppressed, and the operability of the loading and unloading machine 7 can be improved. At the same time, the change of the torque of the output shaft 23 during the switching can be reduced, and the comfort of the wheel loader 1 can be improved.

[0085] The time suitable for power transmission via the direct coupling mechanism 27 is during transportation and the vehicle speed is in the range of 9 to 13 km / h. In addition, it is during return transportation and the vehicle speed is in the range of 9 to 40 km / h. The reason is as follows. That is, the power transmission efficiency of the external lock that transmits power via the direct coupling mechanism 27 is the highest. That is, since the external lock transmits power through the meshing of a pair of gears 27A and 27B, the transmission efficiency is high compared to the internal lock that transmits power via the planetary gear mechanism 29. In addition, when the vehicle speed is below 9 km / h, there is a possibility of suddenly starting excavation during return transportation or transportation. On the other hand, when the power transmission path is switched from the direct coupling mechanism 27 (external lock) to the planetary continuously variable transmission mechanism 24, time may be required for the switch. Therefore, when the vehicle speed is below 9 km / h, it is desirable not to use the direct coupling mechanism 27.

[0086] Table 1 below shows the combination of the power transmission path of the transmission device 21 having both internal locking and external locking. In this case, the multi-speed transmission mechanism 26 has a shift speed of 4 forward speeds and 1 reverse speed. Therefore, when power is transmitted via the direct coupling mechanism 27 (external locking mechanism), the multi-speed transmission mechanism 26 can select the shift speeds of 1 forward speed, 2 forward speeds, 3 forward speeds, 4 forward speeds, and 1 reverse speed.

[0087] [Table 1]

[0088]

[0089]

[0090] In addition, when the speed gear of the multi-speed transmission mechanism 26 is any one of the forward 2nd speed, forward 3rd speed, and forward 4th speed, power can be transmitted through the planetary continuously variable transmission mechanism 24 instead of the direct coupling mechanism 27. At this time, the action of the planetary continuously variable transmission mechanism 24 can be a continuously variable speed action or an internal locking state. However, if the planetary continuously variable speed mechanism 24 is made to perform a continuously variable speed action, the transmission efficiency of the planetary continuously variable speed mechanism 24 becomes lower than that of the internal locking and the external locking. Therefore, since the transmission efficiency of the speed change device 21 is reduced, it is preferred to appropriately select the combination of the power transmission paths shown in the above Table 1.

[0091] Fig.12 The driving force diagram of the transmission device 21 is shown in which both the internal lock and the external lock exist. Fig.12As shown, the forward direction can be shifted into six gears: forward 1st speed continuously variable transmission Lf1, forward 1st speed internal lock Lf2, forward 1st speed external lock Lf3, forward 2nd speed external lock Lf4, forward 3rd speed external lock Lf5, forward 4th speed external lock Lf6. Thus, the ideal driving force line Lf in the forward direction can be infinitely approached.

[0092] On the other hand, the reverse speed can be changed into three gears: reverse 1st speed continuously variable speed Lr1, reverse 1st speed internal lock Lr2, and reverse 1st speed external lock Lr3. As a result, it is possible to infinitely approach the ideal driving force line Lr in the reverse direction. As a result, high traction can be obtained during excavation, high vehicle speed (0-40km / h) can be obtained during return, and stable climbing can be achieved on uphill roads of various slopes.

[0093] In order to achieve a wider speed ratio range, it is preferred to have both "internal locking of the planetary continuously variable transmission mechanism 24" and "external locking by the direct coupling mechanism 27". However, in order to achieve "effectively using the speed range of the planetary continuously variable transmission mechanism 24 while suppressing the change in acceleration and deceleration of the vehicle when switching the power transmission from the continuously variable transmission to the locked state", it may be configured to have only one of the internal locking and the external locking.

[0094] Fig.13 The transmission device 21A of the first modified example is shown, which has only the internal locking of the planetary continuously variable transmission mechanism 24 as a locking method. The transmission device 21A of the first modified example can perform the internal locking action of the planetary continuously variable transmission mechanism 24, but does not have an external locking mechanism (direct coupling mechanism 27). The following Table 2 shows the combination of the power transmission path of the transmission device 21A having only the internal locking.

[0095] [Table 2]

[0096]

[0097] In the first variant, there is one less gear stage based on the direct coupling mechanism 27 (external lock). Therefore, in order to obtain a gear ratio equivalent to that of the transmission device 21 having both internal and external locks, in the first variant, the multi-speed transmission mechanism 26A has five forward gears and two reverse gears. In addition, in the first variant, there is a blocking mechanism 40 for achieving internal lock as described later. In addition, Fig.14 The transmission device 21B of the second modified example is shown. The transmission device 21B of the second modified example also omits the external locking mechanism as in the first modified example. In addition, the second modified example has a brake mechanism 41 for achieving internal locking as described later. Furthermore, Fig.15The transmission 21C of the third modified example is shown. The transmission 21C of the third modified example omits the external lock mechanism, has a brake mechanism 41, and on this basis omits the inertial element 28. That is, in the case of omitting the direct coupling mechanism 27 (external lock), the inertial element 28 can also be omitted.

[0098] Fig.16 The transmission devices 21A, 21B, and 21C ( FIG. 21B ) have a planetary continuously variable transmission mechanism 24 (internal locking) but do not have a direct coupling mechanism 27 (external locking). Fig.13 , Fig.14 , Fig.15 ) driving force line diagram. Fig.16 As shown, the forward speed can be changed into 6 gears, namely, forward 1st speed continuously variable transmission Lf1, forward 1st speed internal lock Lf2, forward 2nd speed internal lock Lf3, forward 3rd speed internal lock Lf4, forward 4th speed internal lock Lf5, and forward 5th speed internal lock Lf6. On the other hand, the reverse speed can be changed into 3 gears, namely, reverse 1st speed continuously variable transmission Lr1, reverse 1st speed internal lock Lr2, and reverse 2nd speed internal lock Lr3.

[0099] In contrast, for example, in the transmission device 21 ( Figure 3 , Figure 4 ) does not perform an internal locking action, and can achieve a configuration with only an external locking action. The following Table 3 shows the combination of the power transmission path of the transmission device 21 with an external locking (direct coupling mechanism 27) but without an internal locking action.

[0100] [Table 3]

[0101]

[0102]

[0103] Fig.17 2 is a driving force diagram of the transmission 21 without internal locking. Fig.17 As shown, the forward speed can be changed into five gears, namely, forward 1st speed continuously variable transmission Lf1, forward 1st speed external lock Lf2, forward 2nd speed external lock Lf3, forward 3rd speed external lock Lf4, and forward 4th speed external lock Lf5. On the other hand, the reverse speed can be changed into two gears, namely, reverse 1st speed continuously variable transmission Lr1 and reverse 1st speed external lock Lr2.

[0104] Next, refer to Figure 3The planetary continuously variable transmission mechanism 24 is described. The planetary continuously variable transmission mechanism 24 includes a planetary gear mechanism 29, a first transmission 33, a second transmission 34, a transmission element 35, a second clutch 36, and a third clutch 37. The planetary gear mechanism 29 is connected to the first output side (first transmission 33 side) via the first connecting member 30. The planetary gear mechanism 29 is connected to the input side (engine 9 side) via the second connecting member 31. The planetary gear mechanism 29 is connected to the second output side (inert element 28 side) via the third connecting member 32.

[0105] The first transmission 33 and the second transmission 34 are composed of an electric motor / generator (electric motor, electric generator) or a hydraulic pump / motor (hydraulic pump, hydraulic motor) and the like. The first transmission 33 and the second transmission 34 are configured so that when the rotation speed of the first transmission 33 is different from the rotation speed of the second transmission 34, stepless speed change can be performed and power can be transmitted between the two. For this purpose, a transmission element 35 for transmitting power between the first transmission 33 and the second transmission 34 is provided between the first transmission 33 and the second transmission 34. The transmission element 35 is composed of, for example, electrical wiring or hydraulic piping. A power storage source 38 can also be installed in the middle of the transmission element 35. The power storage source 38 can be composed of, for example, a hydraulic accumulator or a battery. In addition, the functions of the first transmission 33, the second transmission 34 and the transmission element 35 can be composed of an infinite gear ratio transmission (IVT).

[0106] A second clutch 36 is provided between the planetary gear mechanism 29 and the first transmission 33, that is, between the first connecting member 30 and the first transmission 33. The second clutch 36 is composed of, for example, a clutch (friction plate) based on friction engagement, a dog clutch, or a dog clutch with a synchronizer. The second clutch 36 mechanically couples (connects) and releases the first connecting member 30 and the first transmission 33. That is, the second clutch 36 switches between the planetary gear mechanism 29 and the first transmission 33, and the transmission and release of the power between the planetary gear mechanism 29 and the first transmission 33.

[0107] The controller 25 is composed of, for example, a computing circuit (CPU), a microcomputer having a memory, etc. The controller 25 controls the connection and release of the first clutch 27C, the connection and release of the second clutch 36, and the connection and release of the third clutch 37. The controller 25 controls the rotation speed of the first transmission 33. The controller 25 controls the rotation speed of the second transmission 34 as needed. The controller 25 controls the transmission element 35 and the power storage source 38 as needed. The controller 25 controls the blocking mechanism 40 (described later) as needed. Fig.13 )、Braking mechanism 41( Fig.14 , Fig.15). In addition, the controller 25 controls the connection and release of clutches 58, 59, 60, 66, 67, 68, and 69 of the multi-speed change mechanism 26 described later.

[0108] Here, the controller 25 controls the connection and release of the second clutch 36. For example, when the power transmission based on the planetary continuously variable transmission mechanism 24 is not required, the controller 25 outputs a signal to release the second clutch 36, and releases the second clutch 36. As a result, the rotation of the first transmission 33 can be stopped (or reduced), and the power loss caused by the rotation of the first transmission 33 can be reduced.

[0109] The second transmission 34 is connected to the inert element 28 via the third clutch 37. The third clutch 37 switches the transmission and release of the power between the second transmission 34 and the inert element 28. That is, the third clutch 37 is provided between the second transmission 34 and the inert element 28. The inert element 28 has an idle shaft 28A and an idle gear 28B provided on the idle shaft 28A. The idle shaft 28A is connected to the lock gear 27B of the direct coupling mechanism 27 (more specifically, the rotating shaft 27B1 of the lock gear 27B) via the first clutch 27C.

[0110] In addition, the idle shaft 28A is connected to the second transmission 34 via the transmission 39 and the third clutch 37. The idle gear 28B meshes with the third connecting member 32 and is connected to the planetary gear mechanism 29 via the third connecting member 32. A transmission 39 for changing the speed between the second transmission 34 and the idle element 28 is provided between the second transmission 34 and the idle element 28. The transmission 39 may be omitted. In this case, the third clutch 37 is provided between the idle shaft 28A of the idle element 28 and the rotating shaft of the second transmission 34, and the idle shaft 28A and the rotating shaft of the second transmission 34 can be connected (coupled) and released by the third clutch 37.

[0111] The third clutch 37 is composed of, for example, a clutch (friction plate) based on friction engagement, a dog clutch, or a dog clutch with a synchronizer. The third clutch 37 performs mechanical coupling (connection) and release between the second transmission 34 and the inert element 28. The controller 25 controls the coupling and release of the third clutch 37. For example, when power transmission based on the second transmission 34 is not required, the controller 25 outputs a signal to release the third clutch 37, and releases the third clutch 37. As a result, the rotation of the second transmission 34 can be stopped (or reduced), and the power loss caused by the rotation of the second transmission 34 can be reduced. However, under these conditions, it is not necessary to release the third clutch 37.

[0112] In addition, when the power transmission based on the second transmission 34 is not required, and when the power transmission based on the planetary continuously variable transmission mechanism 24 is not required, for example, it is as described in the following (f) to (i). However, under these conditions (f) to (i), it is not necessary to release the second clutch 36 or the third clutch 37.

[0113] (f) When the power input from the input shaft 22 is transmitted to the inert element 28 via the direct coupling mechanism 27 .

[0114] (g) When the rotation of the first coupling member 30 is fixed by means other than the first transmission 33 (for example, the brake mechanism 41 ), and thereby the planetary continuously variable transmission mechanism 24 is in the internally locked state.

[0115] (h) When the vehicle is stopped.

[0116] (i) When the vehicle is coasting (inertia).

[0117] The power transmitted from the engine 9 to the second connection member 31 is distributed to the first connection member 30 connected to the first transmission 33 and the third connection member 32 connected to the inert element 28 through the planetary gear mechanism 29. The power distributed to the first connection member 30 is transmitted to the inert element 28 through the second clutch 36, the first transmission 33, the transmission element 35, the second transmission 34, the third clutch 37, and the speed changer 39. The power distributed to the third connection member 32 is transmitted to the inert element 28. The distribution ratio of the torque of the first connection member 30 and the third connection member 32 is always fixed, and depends on the form of the planetary gear mechanism 29 and the meshing radius of the gears.

[0118] However, the distribution ratio of the torque of the first connecting member 30 and the third connecting member 32 is fixed. Therefore, the power is not always transferred from the first transmission 33 to the second transmission 34, and sometimes the power is transferred from the second transmission 34 to the first transmission 33. The power transmitted from the third connecting member 32 to the inert element 28 has a smaller loss than the power transmitted from the first connecting member 30 via the first transmission 33 and the second transmission 34. Therefore, the planetary continuously variable transmission mechanism 24 composed of the transmissions 33 and 34 and the planetary gear mechanism 29 has a higher power transmission efficiency than the continuously variable transmission device that transmits power only through the transmission.

[0119] Next, the planetary gear mechanism 29 will be described. Figure 3In the figure, the planetary gear mechanism 29 is represented by a quadrilateral (box). Here, the planetary gear mechanism 29 has three parts (rotating parts), namely, a first part connected to the engine 9 as a power source, a second part connected to the first transmission 33, and a third part connected to the inert element 28 on the output shaft 23 side. Here, in the first embodiment, the planetary gear mechanism 29 is composed of a planetary gear carrier and two sun gears (a first sun gear and a second sun gear). The following Table 4 shows the combination of the constituent elements (planetary gear carrier, a first sun gear, and a second sun gear) of the planetary gear mechanism 29. From the perspective of improving the transmission efficiency of the planetary continuously variable transmission mechanism 24 and constructing the planetary gear mechanism 29 in a small and light weight, "No1-A" in Table 4 is the most suitable.

[0120] [Table 4]

[0121]

[0122] like Figures 4 to 6 As shown, in the first embodiment (i.e., No. 1-A in Table 4), the planetary gear mechanism 29 has a planetary gear carrier 29A corresponding to the first component, a first sun gear 29B corresponding to the second component, a second sun gear 29C corresponding to the third component, a planetary gear 29D, and a balance gear 29E. In addition, the first sun gear 29B, the second sun gear 29C, the planetary gear 29D, and the balance gear 29E can be not only a power transmission based on the meshing of gears (gears), but also a power transmission based on, for example, the friction of the roller (peripheral surface).

[0123] The engine 9 is connected to the planetary gear carrier 29A via the second connecting member 31. The first sun gear 29B is connected to the first transmission 33 via the first connecting member 30. The second sun gear 29C is connected to the idler element 28 (idler gear 28B) via the third connecting member 32. The first sun gear 29B meshes with the planetary gear 29D. The second sun gear 29C meshes with the balance gear 29E. The balance gear 29E meshes with the planetary gear 29D.

[0124] The rotation axis Sp of the planetary gear 29D ( Figure 6 ) and the rotation axis Sb of the balance gear 29E ( Figure 6 ) is supported by the planetary gear carrier 29A. Therefore, the planetary gear 29D and the balance gear 29E are arranged with the center axis S ( Figure 6) as the center while rotating on its own. The planetary gear 29D has a gear portion 29D1 meshing with the first sun gear 29B, and a gear portion 29D2 meshing with the balance gear 29E. The constraint condition for the establishment of the planetary gear mechanism 29 is that the distance between the center axis S of the first sun gear 29B and the rotation axis Sp of the planetary gear 29D is consistent with the distance between the center axis S of the second sun gear 29C and the rotation axis Sp of the planetary gear 29D. Therefore, it is necessary to adjust the number of teeth, the module of the gears, the rotation position of the gears, and the rotation center position of the balance gear 29E of the first sun gear 29B, the planetary gear 29D, the gear portion 29D1 meshing with the first sun gear 29B, the second sun gear 29C, the balance gear 29E, and the gear portion 29D2 meshing with the balance gear 29E so that the above distances are consistent. That is, as long as the above distances can be made equal, for example, the difference in the number of teeth of the first sun gear 29B and the second sun gear 29C can be reduced or the number of teeth can be made the same. Therefore, the reduction ratio of the planetary gear mechanism 29 can be freely set.

[0125] In addition, according to the first embodiment, the balance gear 29E is provided between the second sun gear 29C and the planetary gear 29D, but it may be provided between the first sun gear 29B and the planetary gear 29D. However, in the case where the balance gear 29E is provided on both sides of "between the second sun gear 29C and the planetary gear 29D" and "between the first sun gear 29B and the planetary gear 29D", or in the case where the balance gear 29E is not provided on both sides, power transmission can be performed. However, it is preferred that the balance gear is provided on either side.

[0126] Next, the operation of the planetary gear mechanism 29 composed of the planetary gear carrier 29A and the two sun gears 29B and 29C will be described. Hereinafter, all the conditions of "No1-A", "No1-B" and "No1-C" in Table 4 are satisfied.

[0127] First, the distribution of torque among the three members of the planetary gear mechanism 29 (the carrier 29A and the two sun gears 29B and 29C) will be described. Figure 6This is a cross-sectional view of the planetary gear mechanism 29 as viewed from the power source side. The planetary gear carrier 29A, the first sun gear 29B, and the second sun gear 29C are concentrically arranged. That is, the central axis S (rotational center axis) of the planetary gear carrier 29A, the first sun gear 29B, and the second sun gear 29C are consistent. The first sun gear 29B meshes with the gear portion 29D1 of the planetary gear 29D. The second sun gear 29C meshes with the balance gear 29E. The balance gear 29E meshes with the gear portion 29D2 of the planetary gear 29D. The balance gear 29E and the planetary gear 29D are freely rotatable in the rotational direction through the planetary gear carrier 29A in such a manner that the meshing of the respective gears is established, and are constrained in the revolution direction relative to the central axis S. Therefore, the planetary gear 29D rotates around the rotational axis Sp, which is the central axis of the planetary gear 29D, and revolves around the central axis S of the planetary gear carrier 29A. Therefore, the trajectory Cp of the center axis (rotation axis Sp) of the planetary gear 29D becomes a circle centered on the center axis S of the planetary gear carrier 29A. The balance gear 29E rotates around the rotation axis Sb, which is the center axis of the balance gear 29E, and revolves around the center axis S of the planetary gear carrier 29A. Therefore, the trajectory Cb of the center axis (rotation axis Sb) of the balance gear 29E becomes a circle centered on the center axis S of the planetary gear carrier 29A.

[0128] The meshing radius rs1 of the first sun gear 29B is the meshing radius on the side of the first sun gear 29B when the first sun gear 29B meshes with the planetary gear 29D. The meshing radius rp1 of the gear portion 29D1 of the planetary gear 29D is the meshing radius on the side of the gear portion 29D1 when the first sun gear 29B meshes with the planetary gear 29D. The meshing radius rs2 of the second sun gear 29C is the meshing radius on the side of the second sun gear 29C when the second sun gear 29C meshes with the balance gear 29E. The meshing radius rp2 of the gear portion 29D2 of the planetary gear 29D is the meshing radius on the side of the planetary gear 29D when the balance gear 29E meshes with the planetary gear 29D.

[0129] In the first embodiment (No. 1-A in Table 4), the planetary gear carrier 29A is connected to the second connecting member 31, which is a member connected to the engine 9, and thus the torque Tc of the planetary gear carrier 29A is the torque that can be generated by the engine 9. The first sun gear 29B is connected to the first connecting member 30, which is a member connected to the first transmission 33, and thus the torque Ts1 of the first sun gear 29B is the torque that can be generated by the first transmission 33. The second sun gear 29C is connected to the third connecting member 32, which is a member connected to the idler element 28, and thus the torque Ts2 of the second sun gear 29C is the torque reaction force received from the idler gear 28B.

[0130] Fig.18In the transmission 21D of the fourth modified example (i.e., No. 1-B in Table 4), the first sun gear 29B is connected to the second connecting member 31, which is a member connected to the engine 9, and thus the torque Ts1 of the first sun gear 29B is a torque that can be generated by the engine 9. The planetary gear carrier 29A is connected to the first connecting member 30, which is a member connected to the first transmission 33, and thus the torque Tc of the planetary gear carrier 29A is a torque that can be generated by the first transmission 33. The second sun gear 29C is connected to the third connecting member 32, which is a member connected to the idler element 28, and thus the torque Ts2 of the second sun gear 29C is the torque reaction force received from the idler gear 28B.

[0131] Fig.19 In the transmission 21E of the fifth modification (i.e., No. 1-C in Table 4), the first sun gear 29B is connected to the second connecting member 31, which is a member connected to the engine 9, and thus the torque Ts1 of the first sun gear 29B is a torque that can be generated by the engine 9. The second sun gear 29C is connected to the first connecting member 30, which is a member connected to the first transmission 33, and thus the torque Ts2 of the second sun gear 29C is a torque that can be generated by the first transmission 33. The planetary gear carrier 29A is connected to the third connecting member 32, which is a member connected to the idler element 28, and thus the torque Tc of the planetary gear carrier 29A is the torque reaction force received from the idler gear 28B.

[0132] Next, the relationship between the torque Ts1 of the first sun gear 29B, the torque Ts2 of the second sun gear 29C, and the torque Tc of the planetary gear carrier 29A is explained. First, the first sun gear 29B and the second sun gear 29C are meshed via the planetary gear 29D and the balance gear 29E. In addition, the balance gear 29E and the planetary gear 29D are freely rotated in the rotation direction through the planetary gear carrier 29A, and are constrained in the revolution direction relative to the central axis S of the planetary gear carrier 29A. If the relationship between action and reaction is obtained based on these, the following equations 2, 3, and 4 are established.

[0133] [Formula 2]

[0134]

[0135] [Formula 3]

[0136]

[0137] [Formula 4]

[0138] Tc=Ts1+Ts2

[0139] According to these formulas, the torque Ts1 of the first sun gear 29B, the torque Ts2 of the second sun gear 29C, and the torque Tc of the planetary gear carrier 29A can be calculated based on the meshing radius rp2 of the gear portion 29D2, the meshing radius rs2 of the second sun gear 29C, the meshing radius rp1 of the gear portion 29D1, and the meshing radius rs1 of the first sun gear 29B. The meshing radius rp2 of the gear portion 29D2, the meshing radius rs2 of the second sun gear 29C, the meshing radius rp1 of the gear portion 29D1, and the meshing radius rs1 of the first sun gear 29B are determined by the meshing radius of each gear, and thus cannot be changed during the power transmission of the planetary continuously variable transmission mechanism 24. Therefore, the ratio of the torque Ts1 of the first sun gear 29B, the torque Ts2 of the second sun gear 29C, and the torque Tc of the planetary gear carrier 29A is unchanged during the power transmission of the planetary continuously variable transmission mechanism 24.

[0140] Based on this law, the controller 25 outputs a signal for controlling the first transmission 33 to control the torque of the first connection member 30 (e.g., the first sun gear 29B) connected to the first transmission 33. That is, the controller 25 controls the torque of the first connection member 30 (e.g., the first sun gear 29B) by controlling the first transmission 33. Thus, the controller 25 indirectly controls the torque of the second connection member 31 (e.g., the planetary gear carrier 29A) connected to the engine 9 and the torque of the third connection member 32 (e.g., the second sun gear 29C) connected to the inert element 28. As a result, the transmission torque can be controlled between the second connection member 31 (e.g., the planetary gear carrier 29A) connected to the engine 9 and the third connection member 32 (e.g., the second sun gear 29C) connected to the inert element 28.

[0141] Next, the relationship between the rotation speed of the first sun gear 29B, the rotation speed of the second sun gear 29C, and the rotation speed of the planetary gear carrier 29A is described. First, the first sun gear 29B and the second sun gear 29C are meshed via the planetary gear 29D and the balance gear 29E. In addition, the balance gear 29E and the planetary gear 29D are freely rotated in the rotation direction through the planetary gear carrier 29A, and are constrained in the revolution direction relative to the center axis S of the planetary gear carrier 29A. If the relationship between the rotation speeds is calculated based on these, the following formula 5 holds. In addition, "Ka" in formula 5 is the same as formula 6. In addition, the rotation speed of the planetary gear carrier 29A is set to "Vc", the rotation speed of the first sun gear 29B is set to "Vs1", and the rotation speed of the second sun gear 29C is set to "Vs2".

[0142] [Formula 5]

[0143] Vs2 / Vc=-Ka{Vs1 / Vc}+(Ka-1)

[0144] [Formula 6]

[0145] Ka={rs1×rp2} / {rs2×rp1}

[0146] Figure 7 The relationship of the rotation speed of the planetary gear mechanism 29 is shown. Figure 7 The speed relationship line Y1 in Formula 5 is represented by a line graph. It is assumed that the rotation speed of the planetary gear carrier 29A is fixed. In this case, if the rotation speed of the second sun gear 29C becomes higher, the rotation speed of the first sun gear 29B becomes lower. Conversely, if the rotation speed of the second sun gear 29C becomes lower, the rotation speed of the first sun gear 29B becomes higher. According to this law, the controller 25 outputs a signal to control the first transmission 33 to control the rotation speed of the first connecting member 30 (for example, the first sun gear 29B) connected to the first transmission 33. That is, the controller 25 controls the rotation speed of the first connecting member 30 (for example, the first sun gear 29B) by controlling the first transmission 33. Thus, the controller 25 indirectly controls the rotation speed of the second connecting member 31 (for example, the planetary gear carrier 29A) connected to the engine 9 and the rotation speed of the third connecting member 32 (for example, the second sun gear 29C) connected to the inert element 28. As a result, the speed ratio can be controlled between the second connection member 31 (eg, the planetary carrier 29A) connected to the engine 9 and the third connection member 32 (eg, the second sun gear 29C) connected to the inert element 28 .

[0147] As described above, the planetary gear mechanism 29 needs to make the distance between the center axis S of the first sun gear 29B and the rotation axis Sp of the planetary gear 29D consistent with the distance between the center axis S of the second sun gear 29C and the rotation axis Sp of the planetary gear 29D. That is, as long as these distances are consistent, for example, the meshing radius rs1 of the first sun gear 29B, the meshing radius rp1 of the gear portion 29D1, the meshing radius rs2 of the second sun gear 29C, and the meshing radius rp2 of the gear portion 29D2 can be freely set. Therefore, according to the relationship between the torques Tc, Ts1, and Ts2 (Formula 2, Formula 3, and Formula 4) and the relationship between the rotation speeds Vs1, Vs2, and Vc (Formula 5 and Formula 6), the planetary gear mechanism 29 and the first transmission 33 adjust the meshing radius rs1 of the first sun gear 29B, the meshing radius rp1 of the gear portion 29D1, the meshing radius rs2 of the second sun gear 29C, and the meshing radius rp2 of the gear portion 29D2 in accordance with the torque that can be absorbed and the maximum allowable rotation speed. Thus, the Ka value of Formula 6 is set to an ideal value, and Figure 7The inclination of the speed relationship line Y1 shown is set to an ideal value, thereby making it possible to match the torque and rotational speed of the planetary gear mechanism 29 with both the torque that can be absorbed by the first transmission 33 and the maximum permissible rotational speed. As a result, a small and inexpensive first transmission 33 can be used, and the transmission efficiency of the planetary continuously variable transmission mechanism 24 can be improved.

[0148] In addition, the size and price of the first transmission 33 are proportional to the size of the torque that the first transmission 33 can absorb. Therefore, it is desirable that the absorption torque of the first transmission 33 is small. A specific example is given in the first embodiment (i.e., No. 1-A in Table 4) to illustrate. First, it is desirable to reduce the Ka value of formula 6. Furthermore, the transmission efficiency of the power between the planetary gear mechanism 29 and the inert element 28 is studied. In this case, the transmission efficiency of the power transmission path through the first connecting member 30, the first transmission 33, the transmission element 35, the second transmission 34, the transmission 39 and the third clutch 37 is about 70 to 80%. On the other hand, the transmission efficiency of the power transmission path through the third connecting member 32 is about 99%. Therefore, when the torque allocated to the first transmission 33 is small, the transmission efficiency of the planetary continuously variable transmission mechanism 24 can be improved. Therefore, reducing the Ka value of formula 6 is beneficial to the planetary continuously variable transmission mechanism 24.

[0149] On the other hand, if Figure 7 If the Ka value is reduced in the speed relationship line Y1 shown, the "rotation speed of the first sun gear / rotation speed of the planetary gear carrier (horizontal axis)" will increase when the "rotation speed of the second sun gear / rotation speed of the planetary gear carrier (vertical axis)" is small. The second sun gear 29C is connected to the output shaft 23 via the inert element 28 and the multi-speed change mechanism 26. Therefore, when the "rotation speed of the second sun gear / rotation speed of the planetary gear carrier" is small, the power source (engine 9) is rotating and the vehicle speed is low. That is, if Ka is reduced on the basis of the fixed rotation speed of the planetary gear carrier 29A (rotation speed of the power source), the rotation speed of the first transmission 33 increases when the vehicle is at a low speed. As an example, if a specific example is given, when the "rotation speed of the second sun gear / rotation speed of the planetary gear carrier" is 0, the second sun gear 29C is 0 rotation. The second sun gear 29C is connected to the output shaft 23 via the inert element 28 and the multi-speed change mechanism 26, so that when the second sun gear 29C is 0min -1 In this case, the vehicle speed is 0 km / h. That is, the speed ratio of the planetary continuously variable transmission mechanism 24 is infinite. If the rotation speed limit of the first sun gear 29B is 6000 min -1 If the power source (engine 9) is a diesel engine, the rotation speed of the planetary gear carrier 29A is limited to 2000 min. -1, whereby "rotation speed of the first sun gear / rotation speed of the planetary gear carrier" becomes 3.0. If "rotation speed of the second sun gear / rotation speed of the planetary gear carrier = 0" and "rotation speed of the first sun gear / rotation speed of the planetary gear carrier = 3" are substituted into Formula 5, Ka = 0.5. That is, Ka = 0.5 or so becomes the lower limit. As described above, it is desired that the Ka value is reduced within the range that does not exceed the maximum allowable rotation speed of the first transmission 33. In addition, the planetary gear mechanism 29 composed of the planetary gear carrier and the two sun gears can freely set the meshing radius rs1 of the first sun gear 29B, the meshing radius rp1 of the gear portion 29D1, the meshing radius rs2 of the second sun gear 29C, and the meshing radius rp2 of the gear portion 29D2, thereby freely determining the Ka value. Therefore, it is possible to drive up to the maximum allowable rotation speed of the first transmission 33. Thus, a small and inexpensive first transmission 33 can be used, and the transmission efficiency of the planetary continuously variable transmission mechanism 24 can be improved to 80 to 93%.

[0150] In contrast, the description Fig.19 The fifth variant shown (i.e., No. 1-C in Table 4). In the fifth variant, the first transmission 33 is connected to the second sun gear 29C, and thus, the torque allocated to the first transmission 33 side is Ts2. According to Formula 3, the smaller rs2 and rp1 are, the smaller Ts2 is, and the larger rs1 and rp2 are, the smaller Ts2 is. As mentioned above, the torque allocated to the first transmission 33 side is as small as possible from the perspective of transmission efficiency and the price of the transmission, so it is sufficient to reduce rs2 and rp1 and increase rs1 and rp2. In this case, Ka becomes larger than Formula 6. That is, it can be said that the larger Ka is, the smaller the torque required for the first transmission 33 is. Formula 5 is deformed to derive the following Formula 7. Figure 8 This is a line graph showing Expression 7.

[0151] [Formula 7]

[0152] Vc / Vs1-(1 / (Ka+1))(Vs2 / Vs1)+(ka / (Ka+1))

[0153] As a specific example, the planetary gear carrier 29A is connected to the output shaft 23 via the inertial element 28 and the multi-speed transmission mechanism 26. Therefore, when Vc is 0 min -1 In this case, the vehicle speed is 0 km / h. In this case, "Vc / Vs1" is 0. Here, when the engine 9 serving as the power source is a diesel engine, the maximum rotation speed of the engine 9 is 2000 min -1 So Vs1 is 2000min -1. In addition, the allowable rotation speed (Vs2) of the first connecting member 30 connected to the first transmission 33 is -6000 min -1 Up to 6000min -1 Around. Thus, "Vs2 / Vs1" can take the range of -3 to 3. If "Vc / Vs1=0", "Vs2 / Vs1=-3" are substituted into Formula 7 to obtain Ka, then Ka=3. That is, the upper limit of Ka in this case is around 3. Therefore, it is desired that the Ka value becomes larger within the range that does not exceed the maximum allowable rotational speed of the first transmission 33. And, as described above, the Ka value can be freely determined, thereby enabling driving to the maximum allowable rotational speed of the first transmission 33. Thus, a small and inexpensive first transmission 33 can be used, and the transmission efficiency of the planetary continuously variable transmission mechanism 24 can be increased to 80-93%.

[0154] In contrast, the description Fig.18 The fourth variant shown (i.e., No. 1-B in Table 4). In the fourth variant, the first transmission 33 is connected to the planetary gear carrier 29A, and thus the torque allocated to the first transmission 33 side is Tc. According to Formula 4, on the basis that Ts1 (torque from the engine 9 as the power source) is a fixed value, in order to reduce Tc, it is sufficient to reduce Ts2. According to Formula 3, the smaller rs2 and rp1 are, the smaller Ts2 is, and the larger rs1 and rp2 are, the smaller Ts2 is. As mentioned above, the torque allocated to the first transmission 33 side is preferably reduced in terms of transmission efficiency and the price of the transmission, so it is sufficient to reduce rs2 and rp1 and increase rs1 and rp2. In this case, Ka increases according to Formula 6. That is, it can be said that the larger Ka is, the smaller the torque required for the first transmission 33 is. Formula 5 is deformed to derive the following Formula 8. Fig. 9 This is a line graph representing Expression 8.

[0155] [Formula 8]

[0156] Vs2 / Vs1=(Ka+1)(Vc / Vs1)-ka

[0157] As an example, the second sun gear 29C is connected to the output shaft 23 via the inertial element 28 and the multi-speed transmission mechanism 26, so the vehicle travels at a higher speed when Vs2 rotates at a high speed. The larger the speed change range of the planetary continuously variable transmission mechanism 24, the better, so it is desirable that the maximum value of "Vs2 / Vs1" is larger. However, the allowable rotation speed (Vs2) of the third connecting member 32 connected to the inertial element 28 is 8000min / min. -1 In addition, when the engine 9 serving as the power source is a diesel engine, the maximum rotation speed of the engine 9 is 2000 min -1So Vs1 is 2000min -1 Therefore, the upper limit value of "Vs2 / Vs1" is about 4.0. Furthermore, the allowable rotation speed (Vs2) of the first coupling member 30 connected to the first transmission 33 is -6000 min -1 Up to 6000min -1 . Thus, "Vc / Vs1" can take the range of -3 to 3. If "Vs / Vs1=4.0" and "Vs2 / Vs1=3" are substituted into Formula 8 to obtain Ka, Ka=0.5. That is, Ka becomes the upper limit value at about 0.5. And, as described above, the Ka value can be freely determined, thereby enabling driving to the maximum allowable rotational speed of the first connecting member 30 connected to the first transmission 33. As a result, the transmission torque of the first transmission 33 becomes smaller, and a small and inexpensive first transmission 33 can be used.

[0158] Next, the internal locking action of the planetary continuously variable transmission mechanism 24 is described. The power transmission efficiency of the planetary continuously variable transmission mechanism 24 is 80 to 93%, which is relatively high as a continuously variable transmission. In contrast, for example, the power transmission efficiency of a gear transmission based on the meshing of a pair of gears is about 99%. Therefore, the power transmission efficiency of the planetary continuously variable transmission mechanism 24 is lower than that of a transmission based on the meshing of a pair of gears. Figure 3 To explain the reason.

[0159] That is, the power transmission efficiency between the planetary gear mechanism 29 and the inertial element 28 (idler gear 28B) is considered. Here, the transmission efficiency of the power transmission path through the first connecting member 30, the first transmission 33, the transmission element 35, the second transmission 34, the speed changer 39 and the third clutch 37 is about 70-80%. In contrast, the transmission efficiency of the power transmission path through the third connecting member 32 is about 99%. Therefore, in order to improve the transmission efficiency, it is sufficient to stop the rotation of the first connecting member 30 connected to the first transmission 33 and not transmit power between the first transmission 33 and the second transmission 34. As a result, the power supplied from the engine 9 to the planetary gear mechanism 29 through the second connecting member 31 is not distributed to the first connecting member 30 connected to the first transmission 33, but is all transmitted to the third connecting member 32 connected to the inertial element 28 (idler gear 28B).

[0160] The third connecting member 32 and the idler gear 28B transmit power by meshing the gears with each other, thereby the power supplied from the engine 9 to the planetary gear mechanism 29 through the second connecting member 31 can be transmitted to the idler gear 28B with high efficiency. As a result, the power transmission efficiency of the planetary continuously variable transmission mechanism 24 is improved to about 97%, and the transmission efficiency of the transmission device 21 can be improved. As a result, the wheel loader 1 can save fuel consumption.

[0161] When the planetary continuously variable transmission mechanism 24 performs the internal locking operation, the planetary continuously variable transmission mechanism 24 becomes a fixed speed ratio. Here, if the internal locking speed ratio is set to In, the internal locking speed ratio In can be expressed by the following formula 9. In addition, the rotation speed of the third connecting member 32 is set to "V32", the rotation speed of the second connecting member 31 is set to "V31", and the rotation speed of the first connecting member 30 is set to "V30".

[0162] [Formula 9]

[0163]

[0164] When the internal locking is in effect, the above-mentioned formula 5 also holds true. Therefore, by substituting the rotation speed of the first connecting member 30 connected to the first transmission 33 into the formula 5 as 0, the internal locking speed ratio In can be calculated. For example, in the first embodiment (No. 1-A in Table 4), the rotation speed Vs1 of the first sun gear 29B connected to the first connecting member 30 is substituted into the formula 5 as 0. That is, the internal locking speed ratio In is the following formula 10.

[0165] [Formula 10]

[0166] Vs2 / Vc=Ka+1

[0167] thus

[0168] In=Ka+1

[0169] Fig.18 In the fourth modification (No. 1-B in Table 4) shown, the rotation speed Vc of the planetary carrier 29A connected to the first coupling member 30 is substituted into Formula 8 as 0. That is, the internal lock-up speed ratio In is expressed by Formula 11 below.

[0170] [Formula 11]

[0171] Vs2 / Vs1=-Ka

[0172] thus

[0173] In=-Ka

[0174] Fig.19 In the fifth modification (No. 1-C in Table 4) shown, the rotation speed Vs2 of the second sun gear 29C connected to the first coupling member 30 is substituted into Formula 7 as 0. That is, the internal lock-up speed ratio In is expressed by Formula 12 below.

[0175] [Formula 12]

[0176] Vc / Vs1=Ka / (ka+1)

[0177] thus

[0178] In=Ka / (ka+1)

[0179] In this way, the internal lock speed ratio In depends on the combination of the gears of the planetary gear mechanism 29 and Ka. In order to set the planetary continuously variable transmission mechanism 24 to the internal lock state, it is sufficient to stop the rotation of the first connecting member 30 connected to the first transmission 33 among the three connecting members 30, 31, and 32 connected to the planetary gear mechanism 29. In the case where the first transmission 33 and the second transmission 34 are hydraulic pumps / motors, the controller 25 maintains the volume of the hydraulic pump / motor of the first transmission 33 at a predetermined value or more (preferably 10% or more of the maximum volume), and controls the volume of the hydraulic pump / motor of the second transmission 34 to 0.

[0180] In order to stop the rotation of the first connecting member 30, for example, Fig.13 As shown in the first modification, a blocking mechanism 40 may be provided in the transmission element 35 for transmitting power between the first transmission 33 and the second transmission 34. The blocking mechanism 40 is controlled by the controller 25 to interrupt the power transmission between the first transmission 33 and the second transmission 34.

[0181] For example, in the case where the power transmission of the transmission element 35 is performed by hydraulic pressure, the blocking mechanism 40 can be composed of a hydraulic valve. The controller 25 sends a signal to the blocking mechanism 40 to cut off the flow of hydraulic oil between the first transmission 33 and the second transmission 34. In addition, in the case where the power transmission between the first transmission 33 and the second transmission 34 is performed by electricity, the blocking mechanism 40 can be composed of a converter / inverter. In this case, the converter / inverter applies a simulated resistance between the power lines to increase the voltage between the power lines. In addition, as the blocking mechanism 40, a structure in which the flow of electricity is cut off by a magnetic contactor and a structure in which resistance is applied between the power lines by a resistor can also be adopted. In any case, the controller 25 sends a signal of power transmission and cutoff to the blocking mechanism 40 to control the blocking mechanism 40.

[0182] In addition, the internal locking state can also be achieved by fixing the rotating shaft of the first transmission 33 and the non-rotating portion and stopping the rotation of the first transmission 33. Fig.14 The second variant shown and Fig.15As shown in the third modified example, the first connecting member 30 is fixed to a non-rotating portion (e.g., a housing of the transmission 21) by a brake mechanism 41, thereby achieving an internal locking state. The brake mechanism 41 can adopt a structure that fixes the first connecting member 30 connected to the first transmission 33 to the non-rotating portion by friction coupling or mechanical meshing coupling. In particular, when the first transmission 33 is a generator, it is necessary to flow current to the first transmission 33 (generator) even during the internal locking action. Therefore, from the perspective of power loss, it is desirable to fix the first connecting member 30 to the non-rotating portion by the brake mechanism 41. That is, when the first transmission 33 is a generator, from the perspective of power loss, it is desirable to fix the first connecting member 30 to the non-rotating portion by the brake mechanism 41. As a result, the power transmission of the planetary continuously variable transmission mechanism 24 during internal locking can be improved, and the wheel loader 1 can save fuel consumption.

[0183] also, Figures 13 to 15 The transmissions 21A, 21B, and 21C of the first to third modified examples shown can perform an internal locking action of the planetary continuously variable transmission mechanism 24, but do not have an external locking mechanism (direct coupling mechanism 27). In the case of such transmissions 21A, 21B, and 21C, when starting and digging, the planetary continuously variable transmission mechanism 24 is continuously variable to transmit power, and when transporting and returning, the planetary continuously variable transmission mechanism 24 is internally locked to transmit power. As a result, when starting and digging (vehicle speed 0 to 7 km / h) when continuously variable speed change is required, the power transmission efficiency can be improved by the stepless change achieved by the planetary continuously variable transmission mechanism 24. On the other hand, when transporting and returning (vehicle speed 7 km / h or more) when continuously variable speed change is not required, the planetary continuously variable transmission mechanism 24 can be internally locked to further improve the transmission efficiency compared with continuously variable speed change. As a result, the wheel loader 1 can save fuel consumption.

[0184] Next, refer to Figure 3Next, the direct coupling mechanism 27 as the external locking mechanism is described. The direct coupling mechanism 27 transmits the power supplied from the engine 9 to the idler gear 28B through the meshing of the gears without passing through the planetary continuously variable transmission mechanism 24. The power transmission efficiency of the direct coupling mechanism 27 is about 99%, thereby improving the transmission efficiency of the transmission device 21 and saving fuel consumption of the wheel loader 1. The direct coupling mechanism 27 includes an input gear 27A provided on the input shaft 22, a lock gear 27B meshing with the input gear 27A, and a first clutch 27C. The rotating shaft 27B1 provided with the lock gear 27B is connected to the idler shaft 28A of the idler element 28 via the first clutch 27C. The first clutch 27C is composed of, for example, a clutch (friction plate) based on friction engagement, a dog clutch, or a dog clutch with a synchronizer. The first clutch 27C performs mechanical coupling (connection) and release between the lock gear 27B and the idler gear 28B. By releasing the second clutch 36 and engaging the first clutch 27C, the power input from the input shaft 22 is transmitted to the idler gear 28B via the input gear 27A, the lock gear 27B, and the first clutch 27C. Thus, the power supplied from the engine 9 can be transmitted to the idler gear 28B via the direct coupling mechanism 27 as an external locking mechanism, not via the planetary continuously variable transmission mechanism 24.

[0185] Planetary continuously variable transmission mechanism 24 Figure 7 The characteristics of the planetary gear mechanism 29 shown in the speed relationship line Y1 can increase the speed of the third connection member 32 connected to the idler 28B relative to the second connection member 31 connected to the power source (engine 9). In order to effectively use the speed increase range of the planetary continuously variable transmission mechanism 24, it is preferred that the power transmission via the direct connection mechanism 27 can increase the speed. Here, when the rotation speeds of the first connection member 30 connected to the first transmission 33 and the third connection member 32 connected to the idler 28B among the three connection members 30, 31, and 32 connected to the planetary gear mechanism 29 are the same, the rotation speeds of the second connection member 31 connected to the engine 9 and the third connection member 32 connected to the idler 28B become the same.

[0186] The rotation speed of the idler gear 28B at this time is expressed by the following equation 13. In addition, the rotation speed of the idler gear 28B is set to "V28B", the rotation speed of the second connecting member 31 connected to the engine 9 is set to "V31", the number of teeth of the third connecting member 32 connected to the idler gear 28B is set to "N32", and the number of teeth of the idler gear 28B is set to "N28B".

[0187] [Formula 13]

[0188] V28B=V31×(N32 / N28B)

[0189] Here, the synchronous rotation speed ratio Id is defined as in the following equation 14. In addition, the number of teeth of the third coupling member 32 is denoted as “N32”, and the number of teeth of the idler gear 28B is denoted as “N28B”.

[0190] [Formula 14]

[0191] Id=N32 / N28B

[0192] The external lockup rotation speed ratio Ir is defined as in the following equation 15. The number of teeth of the input gear 27A is denoted as “N27A”, and the number of teeth of the lockup gear 27B is denoted as “N27B”.

[0193] [Formula 15]

[0194] Ir=N27A / N27B

[0195] In this case, by making the external locking rotation speed ratio Ir greater than the synchronous rotation speed ratio Id, the speed increase range of the planetary continuously variable transmission mechanism 24 can be effectively used. For example, in the case of a transmission device 21 having an external lock but not performing an internal locking action, power transmission is performed as follows. That is, during starting and digging (vehicle speed 0 to 7 km / h) when continuously variable transmission is required, power transmission is performed via the planetary continuously variable transmission mechanism 24. During transportation and return (vehicle speed 7 km / h or more) when continuously variable transmission is not required, power transmission is performed via the external locking mechanism (direct coupling mechanism 27).

[0196] On the other hand, in the case of a transmission 21 having an external locking mechanism (direct-connection mechanism 27) and performing an internal locking action, it is desirable to set the external locking rotational speed ratio Ir to be greater than the internal locking speed ratio In. In this case, for example, power transmission is performed as follows. During starting and excavation (vehicle speed 0 to 7 km / h) when continuously variable speed change is required, power transmission is performed while continuously variable speed change is performed via the planetary continuously variable speed change mechanism 24. During transportation and return transportation (vehicle speed 7 km / h or more) when continuously variable speed change is not required, power transmission is performed while internal locking action is performed via the planetary continuously variable speed change mechanism 24. During transportation and return transportation (vehicle speed 10 km / h or more) when continuously variable speed change is not required, power transmission is performed via the external locking mechanism (direct-connection mechanism 27). As a result, the transmission 21 can select the power transmission path with the highest power transmission efficiency during all actions of excavation, starting, transportation, and return transportation. As a result, the wheel loader 1 can save fuel consumption.

[0197] Next, the multi-speed transmission mechanism 26 will be described. The multi-speed transmission mechanism 26 is a transmission mechanism that changes speed by meshing gears, switching clutches, and switching brakes. The multi-speed transmission mechanism 26 is equivalent to, for example, a planetary transmission, a parallel-axle transmission, a manual transmission, an automatic transmission, a dual-clutch transmission, etc. In the first embodiment, the multi-speed transmission mechanism 26 is composed of a dual-clutch transmission with 4 forward speeds and 1 reverse speed. In contrast, Fig.13 The first variant shown in FIG. Fig.14 The second variant shown, Fig.15 In the third modified example shown, the multi-speed transmission mechanism 26A is composed of a dual clutch transmission with 5 forward speeds and 2 reverse speeds. In addition, the multi-speed transmission mechanism 26, 26A is not limited to these structures, and for example, it is conceivable to shift from 1st to 16th speeds in forward movement and from 1st to 8th speeds in reverse movement.

[0198] Reference Fig.10 The multi-speed transmission mechanism 26 as a dual clutch transmission will be described. The multi-speed transmission mechanism 26 has an odd-numbered shaft 51, an even-numbered shaft 52, an output shaft 53, and a counter gear 54. The output shaft 53 of the multi-speed transmission mechanism 26 also corresponds to the output shaft 23 of the transmission 21. The odd-numbered shaft 51 is composed of an odd-numbered gear 55, a forward first-speed gear 56, a forward third-speed gear 57, a fourth clutch 58 as a first output clutch, a sixth clutch 59, an eighth clutch 60, and an odd-numbered shaft 61. The even-numbered shaft 52 is composed of an even-numbered gear 62, a forward second-speed gear 63, a forward fourth-speed gear 64, a reverse first-speed gear 65, a fifth clutch 66 as a second output clutch, a seventh clutch 67, a tenth clutch 68, a ninth clutch 69, and an even-numbered shaft 70.

[0199] The counter gear 54 is a gear for reversing the rotation direction of the output shaft 53. The output shaft 53 is composed of a forward first-speed output gear 71, a forward second-speed output gear 72, a forward third-speed output gear 73, a forward fourth-speed output gear 74, and a reverse first-speed output gear 75. The even-numbered gear 62 and the odd-numbered gear 55 are always meshed with the idler gear 28B and rotate together with the idler gear 28B. In addition, the forward first-speed gear 56 is always meshed with the forward first-speed output gear 71, the forward second-speed gear 63 is always meshed with the forward second-speed output gear 72, the forward third-speed gear 57 is always meshed with the forward third-speed output gear 73, and the forward fourth-speed gear 64 is always meshed with the forward fourth-speed output gear 74. In addition, the reverse first-speed gear 65, the counter gear 54, and the reverse first-speed output gear 75 are also always meshed. The fourth clutch 58 couples (connects) and releases the odd-numbered gear 55 with the odd-numbered gear shaft 61. The fourth clutch 58 couples the odd-numbered gear 55 with the odd-numbered gear shaft 61, thereby enabling power transmission between the idler gear 28B and the odd-numbered gear shaft 61. The fifth clutch 66 couples (connects) and releases the even-numbered gear 62 with the even-numbered gear shaft 70. The fifth clutch 66 couples the even-numbered gear 62 with the even-numbered gear shaft 70, thereby enabling power transmission between the idler gear 28B and the even-numbered gear shaft 70.

[0200] The sixth clutch 59 couples (connects) and releases the forward 1st speed gear 56 and the odd-numbered shaft 61. The forward 1st speed gear 56 is coupled to the odd-numbered shaft 61 by the sixth clutch 59, thereby enabling power transmission between the output shaft 53 and the odd-numbered shaft 61. The forward 3rd speed gear 57 is coupled to the odd-numbered shaft 61 by the eighth clutch 60, thereby enabling power transmission between the output shaft 53 and the odd-numbered shaft 61. The forward 2nd speed gear 63 is coupled to the even-numbered shaft 70 by the seventh clutch 67, thereby enabling power transmission between the output shaft 53 and the even-numbered shaft 70. The forward 4th speed gear 64 is coupled to the even-numbered shaft 70 by the tenth clutch 68, thereby enabling power transmission between the output shaft 53 and the even-numbered shaft 70. The reverse 1st speed gear 65 is coupled to the even-numbered shaft 70 by the ninth clutch 69, thereby enabling power transmission between the output shaft 53 and the even-numbered shaft 70. The sixth clutch 59 , the seventh clutch 67 , the eighth clutch 60 , the ninth clutch 69 , and the tenth clutch 68 are constituted by dog ​​clutches or dog clutches with synchronizers.

[0201] Next, the operation of the multi-speed transmission mechanism 26 will be described. In order to transmit the power input to the idler gear 28B to the output shaft 53 at the forward first speed, the fourth clutch 58 is engaged, the fifth clutch 66 is released, the sixth clutch 59 is engaged, and the eighth clutch 60 is released. In this state, any two or more clutches among the seventh clutch 67, the tenth clutch 68, and the ninth clutch 69 are released. The forward first speed corresponds to No. 1 to No. 4 in Table 5 described later.

[0202] In order to transmit power to the output shaft 53 at the forward second speed, the fifth clutch 66 and the seventh clutch 67 are engaged, and the fourth clutch 58, the tenth clutch 68, and the ninth clutch 69 are released. In this state, one or both of the sixth clutch 59 and the eighth clutch 60 are released. The forward second speed corresponds to No. 9 to No. 11 in Table 5 described later.

[0203] In order to transmit power to the output shaft 53 at the forward third speed, the fourth clutch 58 and the eighth clutch 60 are engaged, and the fifth clutch 66 and the sixth clutch 59 are released. In this state, any two or more of the seventh clutch 67, the tenth clutch 68, and the ninth clutch 69 are released. The forward third speed corresponds to No. 5 to No. 8 in Table 5 described later.

[0204] In order to transmit power to the output shaft 53 at the fourth forward speed, the fifth clutch 66 and the tenth clutch 68 are engaged, and the fourth clutch 58, the seventh clutch 67, and the ninth clutch 69 are released. In this state, one or both of the sixth clutch 59 and the eighth clutch 60 are released. The fourth forward speed corresponds to No. 12 to No. 14 in Table 5 described later.

[0205] In order to transmit power to the output shaft 53 in the first reverse speed, the fifth clutch 66 and the ninth clutch 69 are engaged, and the fourth clutch 58, the seventh clutch 67, and the tenth clutch 68 are released. In this state, one or both of the sixth clutch 59 and the eighth clutch 60 are released. The first reverse speed corresponds to No. 15 to No. 17 in Table 5 described later.

[0206] When power is transmitted from the idler gear 28B to the output shaft 53 via the odd-numbered shaft 51, the seventh clutch 67, the tenth clutch 68, and the ninth clutch 69 can be switched between engagement and release. Thus, any one of the forward 2nd speed gear 63, the forward 4th speed gear 64, or the reverse 1st speed gear 65 can be pre-engaged with the even-numbered gear shaft 70. Similarly, when power is transmitted from the idler gear 28B to the output shaft 53 via the even-numbered shaft 52, the sixth clutch 59 and the eighth clutch 60 can be switched between engagement and release. Thus, any one of the forward 1st speed gear 56 or the forward 3rd speed gear 57 can be pre-engaged with the odd-numbered gear shaft 61.

[0207] The power transmission from the idler gear 28B to the output shaft 53 can be switched from the mode via the odd-numbered gear shaft 61 to the mode via the even-numbered gear shaft 70 by releasing the fourth clutch 58 and engaging the fifth clutch 66 while the fourth clutch 58 is engaged and the fifth clutch 66 is released. Similarly, the power transmission from the idler gear 28B to the output shaft 53 can be switched from the mode via the even-numbered gear shaft 70 to the mode via the odd-numbered gear shaft 61 by releasing the fourth clutch 58 and engaging the fifth clutch 66 while the fourth clutch 58 is released and the fifth clutch 66 is engaged.

[0208] However, the switching of the engagement of the fourth clutch 58 and the fifth clutch 66 does not necessarily have to be performed alternately. For example, there is a switching from No. 1 to 4 to No. 5 to 8, and a switching from No. 5 to 8 to No. 1 to 4 as shown in Table 5 below. In this case, after the fourth clutch 58 is released, the sixth clutch 59 and the eighth clutch 60 are engaged or released. Then, the released fourth clutch 58 is engaged. In addition, there is a switching from No. 9 to 11 to No. 12 to 14, a switching from No. 12 to 14 to No. 9 to 11, a switching from No. 9 to 11 to No. 15 to 17, a switching from No. 15 to 17 to No. 9 to 11, a switching from No. 12 to 14 to No. 15 to 17, and a switching from No. 15 to 17 to No. 12 to 14. In this case, after the fifth clutch 66 is released, the seventh clutch 67, the tenth clutch 68, and the ninth clutch 69 are engaged or released. Then, the released fifth clutch 66 is engaged.

[0209] [Table 5]

[0210]

[0211]

[0212] In addition, when the wheel loader 1 performs a V-type cycle mainly for loading gravel or the like into a dump truck, the vehicle is moved forward to excavate gravel or the like, and then the vehicle is moved toward the dump truck. In this case, a specific example in the first embodiment (i.e., No. 1-A in Table 4) is cited for explanation. The planetary continuously variable transmission mechanism 24 is based on Figure 7 By controlling the rotation speed of the first connecting member 30 connected to the first transmission 33 according to the relationship of the speed relationship line Y1 of the planetary gear mechanism 29 shown in FIG. 1 , the rotation direction of the third connecting member 32 connected to the idler gear 28B can be reversed. However, in the case where the rotation direction of the second sun gear 29C is to be reversed relative to the rotation direction of the first sun gear 29B (i.e., to the Figure 7In the case of the right lower direction control), the rotation speed of the first sun gear 29B becomes higher. Similarly, in the case of wanting to reverse the rotation direction of the first sun gear 29B relative to the rotation direction of the second sun gear 29C (towards Figure 7 In the case of upper left direction control), the rotation speed of the second sun gear 29C becomes higher.

[0213] In such a case, the first transmission 33 connected to the first connecting member 30 has to adopt a device with a higher maximum rotation speed limit. Therefore, in order to make the first connecting member 30 connected to the first transmission 33 rotate at a high speed and change the rotation direction of the third connecting member 32 connected to the idler 28B from forward rotation to reverse rotation, an expensive first transmission 33 with a high maximum rotation speed is adopted. As a result, there is a possibility that the original price of the planetary continuously variable transmission mechanism 24 will increase. Therefore, it is desired to use the multi-stage transmission mechanism 26 when the wheel loader 1 moves backward so that the rotation direction of the output shaft 53 (output shaft 23) is reversed from the forward direction to the reverse direction. As a result, the rotation speed of the first transmission 33 connected during the reverse rotation can be reduced, and the cheap first transmission 33 can be used. In addition, although the first embodiment (i.e., No. 1-A in Table 4) is taken as an example, in the case of the fourth variant (i.e., No. 1-B in Table 4) and the fifth variant (i.e., No. 1-C in Table 4), similarly, a multi-speed transmission mechanism 26 is used to switch the rotation direction of the output shaft 53, thereby switching the forward direction and the reverse direction. This method can reduce the rotation speed of the first transmission 33 connected during reversing, and can use an inexpensive first transmission 33.

[0214] As described above, according to the first embodiment, the transmission 21 includes the input shaft 22 (input member) connected to the power source (engine 9), the output shaft 23 (output member) connected to the load (front shaft 12, rear shaft 13), the planetary gear mechanism 29 (planetary mechanism) provided between the input shaft 22 and the output shaft 23, the first transmission 33 connected to the planetary gear mechanism 29, the second transmission 34 provided separately from the first transmission 33, and the controller 25 for changing the rotation speed of the first transmission 33. The planetary gear mechanism 29 is composed of the following three components (rotational components): the planetary gear carrier 29A, the first sun gear 29B (first sun gear component) rotating around the rotation center axis of the planetary gear carrier 29A, and the second sun gear 29C (second sun gear component) rotating around the rotation center axis of the planetary gear carrier 29A.

[0215] In this case, for example, Figure 4 as well as Figure 5As shown, the planetary gear carrier 29A, which is one of the three components and is the first component, is connected to the input shaft 22 via the second connecting member 31 (another component). The first sun gear 29B, which is the second component other than the planetary gear carrier 29A, is connected to the first transmission 33 via the first connecting member 30 and the second clutch 36 (all other components). The second sun gear 29C, which is the third component other than the planetary gear carrier 29A and the first sun gear 29B, is connected to the output shaft 23 via the third connecting member 32, the inert element 28, and the multi-speed transmission mechanism 26 (all other components). In addition, the planetary gear carrier 29A (the first component) may be directly connected to the input shaft 22. The first sun gear 29B (the second component) may be directly connected to the first transmission 33. The second sun gear 29C (the third component) may be directly connected to the output shaft 23.

[0216] Here, the planetary gear carrier 29A supports a planetary gear 29D (planetary component) that transmits power while rotating with the first sun gear 29B and the second sun gear 29C while revolving around the rotation center axis S of the planetary gear carrier 29A, and a balance gear 29E (balance component) that serves as a counter gear. In addition, the planetary gear mechanism 29 distributes the torque transmitted from the engine 9 to the planetary gear carrier 29A (first component) of the planetary gear mechanism 29 to the first sun gear 29B (second component) and the second sun gear 29C (third component). The planetary gear mechanism 29 performs a rotational motion with two degrees of freedom between the planetary gear carrier 29A, the first sun gear 29B, and the second sun gear 29C. The second transmission 34 transmits the power transmitted from the first transmission 33 to the load (output shaft 23) or the power source (input shaft 22), or transmits the power transmitted from the load (output shaft 23) or the power source (input shaft 22) to the first transmission 33. Furthermore, the controller 25 changes the rotation speed of the output shaft 23 relative to the rotation speed of the input shaft 22 by changing the rotation speed of the first transmission 33 .

[0217] That is, the speed change device 21 of the first embodiment performs stepless speed change through the planetary gear mechanism 29, and transmits the power from the power source (input shaft 22) to the load (output shaft 23), or transmits the power from the load (output shaft 23) to the power source (input shaft 22). In this case, the speed change device 21 includes the planetary gear mechanism 29 provided between the input shaft 22 and the output shaft 23, the first transmission 33 connected to the planetary gear mechanism 29, and the second transmission 34 that transmits the power transmitted from the first transmission 33 to the load or the power source. In addition, the planetary gear mechanism 29 includes: a planetary gear carrier 29A connected to the input shaft 22 and supporting a planetary gear 29D and a balance gear 29E; a first sun gear 29B connected to the first transmission 33; and a second sun gear 29C connected to the output shaft 23 via an inert element 28 and a multi-speed change mechanism 26. In addition, the speed change device 21 has at least one of an internal lock and an external lock (direct coupling mechanism 27). Furthermore, the transmission 21 can switch between power transmission by the planetary continuously variable transmission mechanism 24 and power transmission by locking.

[0218] Therefore, a transmission device 21 with high transmission efficiency can be provided, and the power loss of the wheel loader 1 as a working vehicle can be reduced. In this case, the speed range of the planetary continuously variable transmission mechanism 24 including the planetary gear mechanism 29, the first transmission 33 and the second transmission 34 can be effectively used. On this basis, when the power transmission based on the planetary continuously variable transmission mechanism 24 is switched to the power transmission based on the lock, the change of the acceleration and deceleration of the vehicle can be reduced. Moreover, when the upper limit value of the rotation speed of the first transmission 33 and the upper limit value of the torque that can be generated (absorbed) are limited, a gear arrangement with an optimal gear ratio of the planetary gear mechanism 29 can be provided, and the transmission efficiency of the planetary continuously variable transmission mechanism 24 can be improved. That is, even when using a cheap and small first transmission 33 with limited upper limits of the rotation speed and the upper limit value of the torque that can be generated (absorbed) is used, the transmission efficiency of the planetary continuously variable transmission mechanism 24 can be improved.

[0219] For example, in the first embodiment, power transmission based on the locking mechanism is performed under the condition that the loading and unloading machine 7 is not operated or high operability of the loading and unloading machine 7 is not required. Therefore, in this case, power transmission (internal locking, external locking) can be performed by meshing of gears with high transmission efficiency. On the other hand, power transmission based on the planetary continuously variable transmission mechanism 24 is performed under the condition that the loading and unloading machine 7 is operated or high operability of the loading and unloading machine 7 is required. Therefore, the planetary continuously variable transmission mechanism 24 can be operated to perform stepless speed change. In addition, the power transmission based on the planetary continuously variable transmission mechanism 24 has the possibility of lower transmission efficiency compared with the power transmission (internal locking, external locking) performed only by meshing of gears. However, the stepless speed change based on the planetary continuously variable transmission mechanism 24 can improve the transmission efficiency compared with the stepless speed change based on the torque inverter. Thus, when the power of one engine 9 is distributed to the "speed change device 21 for driving the vehicle" and the "hydraulic pump 10 for operating the loading and unloading machine 7", the change in the rotation speed of the engine 9 caused by the speed change of the speed change device 21 can be smoothed. Therefore, it is possible to suppress the abrupt change in the operating speed of the loading and unloading machine 7, and improve the operability of the loading and unloading machine 7. On this basis, when the power of one engine 9 is distributed to the speed change device 21 and the hydraulic pump 10, the power loss caused by the distribution can be reduced.

[0220] According to the first embodiment, the controller 25 stops the rotation of the first sun gear 29B (second component) of the planetary gear mechanism 29 to achieve an internal locked state. That is, the controller 25 stops the rotation of the first sun gear 29B and changes the state of performing a rotational motion with two degrees of freedom between the planetary gear carrier 29A, the first sun gear 29B and the second sun gear 29C to a state of performing a rotational motion with a single degree of freedom. Thus, the speed change device 21 transmits the power transmitted from the power source to the planetary gear mechanism 29 to the load when the planetary gear mechanism 29 is in a single degree of freedom state. At this time, the controller 25 outputs a command to make the rotation speed 0 to the first transmission 33. Or the controller 25 outputs a command to stop the rotation of the component connected to the first transmission 33 by mechanical coupling. Or the controller 25 outputs a command to cut off the power transmitted from the first transmission 33 to the second transmission 34. Thus, the controller 25 stops the rotation of the first sun gear 29B. In either case, by stopping the rotation of the first sun gear 29B of the planetary gear mechanism 29 , internal locking can be achieved, and the transmission efficiency can be improved.

[0221] According to the first embodiment, the transmission 21 has two power transmission paths, namely, a first power transmission path (planetary continuously variable transmission mechanism 24) and a second power transmission path (direct coupling mechanism 27). That is, the power transmission path for transmitting power from the power source to the load (output shaft 23) through the planetary gear mechanism 29 is set as the first power transmission path. In this case, in the transmission 21, a second power transmission path is provided in parallel with the first power transmission path. The second power transmission path is a direct coupling mechanism 27 (external locking mechanism) for transmitting power to the load (output shaft 23) through the meshing of gears without passing through the planetary gear mechanism 29. The second power transmission path (direct coupling mechanism 27) has a first clutch 27C that switches between connection and release. The controller 25 connects the first clutch 27C and transmits power through the second power transmission path (direct coupling mechanism 27). As a result, for example, compared with a configuration in which only internal locking is performed, the transmission efficiency can be improved.

[0222] According to the first embodiment, the speed ratio when the rotation speed of the planetary gear carrier 29A (the first component) and the rotation speed of the second sun gear 29C (the third component) are the same is set as the synchronous rotation speed ratio. In addition, the value obtained by dividing the rotation speed of the second sun gear 29C (the third component) by the rotation speed of the power source when power is transmitted via the second power transmission path (the direct coupling mechanism 27) by connecting the first clutch 27C is set as the locking rotation speed ratio. In this case, the locking rotation speed ratio is greater than the synchronous rotation speed ratio. Therefore, when power is transmitted through the second power transmission path as an external locking mechanism, the speed can be increased.

[0223] According to the first embodiment, a second clutch 36 for switching the transmission and release of power between the first sun gear 29B (second component) and the first transmission 33 is provided between the first sun gear 29B (second component) and the first transmission 33. Furthermore, when the working vehicle (wheel loader 1) stops, the controller 25 disconnects the power transmission between the first sun gear 29B (second component) and the first transmission 33 by releasing the second clutch 36. Thus, when the vehicle speed of the wheel loader 1 is 0, the power transmission to the first transmission 33 can be prevented.

[0224] According to the first embodiment, the controller 25 connects the second clutch 36 in order to stop the first sun gear 29B (the second component). Therefore, when the internal lock is on, the rotation of the first sun gear 29B (the second component) can be stopped. In addition, in the first embodiment, a third clutch 37 is provided between the second transmission 34 and the load or power source to switch the transmission and release of power between the second transmission 34 and the load or power source. And, when the first sun gear 29B (the second component) stops, the controller 25 releases the third clutch 37. Therefore, when the internal lock is on, the power transmission to the second transmission 34 can be prevented. In addition, when the internal lock is on, the second clutch 36 must be connected, but the third clutch 37 can be either released or connected.

[0225] According to the first embodiment, the controller 25 releases the second clutch 36 when the first clutch 27C is connected. Therefore, when the external lock is on, the power transmission to the first transmission 33 can be blocked. In addition, the controller 25 releases the third clutch 37 when the first clutch 27C is connected. Therefore, when the external lock is on, the power transmission to the second transmission 34 can be blocked. In addition, when the external lock is on, the second clutch 36 and the third clutch 37 can be either released or connected.

[0226] According to the first embodiment, the transmission 21 is provided with a multi-speed transmission mechanism 26 between the second sun gear 29C (third component) and the output shaft 23 (output component). The multi-speed transmission mechanism 26 has a first output transmission path (odd-numbered shaft 51) and a second output transmission path (even-numbered shaft 52). In this case, the first output transmission path (odd-numbered shaft 51) is between the second sun gear 29C (third component) and the output shaft 23 (output component), and the number of gear meshing is odd. The second output transmission path (even-numbered shaft 52) ​​is between the second sun gear 29C (third component) and the output shaft 23 (output component), and the number of gear meshing is both odd and even. Specifically, the path in the second output transmission path (even-numbered shaft 52) ​​that transmits from the idler gear 28B to the output shaft 53 via the even-numbered gear 62, the fifth clutch 66, the ninth clutch 69, the counter gear 54, and the first reverse gear 75 is an even number of gear meshing. The number of gear meshing between the second sun gear 29C (third component) based on other paths and the output shaft 23 (output component) is an odd number of times. In addition, the first output transmission path (odd-numbered shaft 51) has a first output clutch (fourth clutch 58, sixth clutch 59, eighth clutch 60) for switching the transmission and release of the power of the first output transmission path. The second output transmission path (even-numbered shaft 52) ​​has a second output clutch (fifth clutch 66, seventh clutch 67, tenth clutch 68, ninth clutch 69) for switching the transmission and release of the power of the second output transmission path. The controller 25 reverses the traveling direction of the wheel loader 1 (vehicle) by switching between a forward mode (e.g., first speed mode) in which the first output clutch (e.g., fourth clutch 58, sixth clutch 59) is connected and the second output clutch (e.g., fifth clutch 66) is released, and a reverse mode (reverse mode) in which the first output clutch (e.g., fourth clutch 58) is released and the second output clutch (e.g., fifth clutch 66, ninth clutch 69) is connected. Therefore, the speed change device 21 can reverse the rotation direction of the load (output shaft 23).

[0227] According to the first embodiment, the multi-speed transmission mechanism 26 as a sub-speed transmission mechanism is provided in the transmission device 21. In addition, the second transmission 34 is connected to the inert element (specifically, the idler gear 28B as a rotating element) provided between the planetary gear mechanism 29 and the multi-speed transmission mechanism 26. Fig. 20 As shown in the sixth modification, the second transmission 34 may be connected to the output shaft 23 (output member). Figures 30 to 39As shown, the second transmission 34 can be configured to be connected to the following rotating elements, including a rotating element provided between the input shaft 22 (input component) and the drive source (engine 9), a rotating element constituting the multi-speed transmission mechanism 26, a rotating element provided between the multi-speed transmission mechanism 26 and the output shaft 23 (output component), the output shaft 23 (output component), or a rotating element provided between the output shaft 23 and a load.

[0228] then, Figure 21 to Figure 24 The second embodiment is shown. The second embodiment is characterized in that a planetary gear mechanism is formed by a planetary carrier, a sun gear, and a ring gear. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and their description is omitted.

[0229] In the first embodiment, the case where the planetary gear mechanism 29 of the planetary continuously variable transmission mechanism 24 is composed of a planetary gear carrier and two sun gears is described as an example. In contrast, in the second embodiment, the planetary gear mechanism 81 of the planetary continuously variable transmission mechanism 24 is composed of a planetary gear carrier 81A, a sun gear 81B and a ring gear 81C. The following Table 6 shows the combination of the constituent elements (planetary gear carrier, sun gear, ring gear) of the planetary gear mechanism 81. Power transmission can be performed under any circumstances. From the perspective of being able to improve the transmission efficiency of the planetary continuously variable transmission mechanism 24, being able to reduce the maximum absorption torque of the first transmission 33, and being able to construct the entire planetary continuously variable transmission mechanism 24 in a small and lightweight manner, "No2-A" in Table 6 is the most appropriate.

[0230] [Table 6]

[0231]

[0232] like Fig.21 as well as Fig. 22 As shown, in the second embodiment, the planetary gear mechanism 81 has a planetary gear carrier 81A corresponding to the first component, a sun gear 81B corresponding to the second component, a ring gear 81C corresponding to the third component, and a planetary gear 81D. In addition, the sun gear 81B, the ring gear 81C, and the planetary gear 81D may not be based on the power transmission of the meshing of the gears (gears), for example, the power transmission may be based on the friction of the roller (peripheral surface).

[0233] The engine 9 is connected to the planetary gear carrier 81A via the second connecting member 31. The sun gear 81B is connected to the first transmission 33 via the first connecting member 30. The ring gear 81C is connected to the idler element 28 (idler gear 28B) via the third connecting member 32. The sun gear 81B meshes with the planetary gear 81D. In addition, the planetary gear 81D meshes with the ring gear 81C. The rotation axis Sp ( Fig.23 ) is supported by the planetary gear carrier 81A. Therefore, the planetary gear 81D is supported by the center axis S ( Fig.23 ) is the center of the universe and rotates on its own axis.

[0234] Next, the operation of the planetary gear mechanism 81 composed of the planetary gear carrier 81A, the sun gear 81B and the ring gear 81C will be described. The following is true under all the conditions of "No2-A", "No2-B", "No2-C", "No2-D" and "No2-F" in Table 6.

[0235] First, the distribution of torque among the three members (the carrier 81A, the sun gear 81B, and the ring gear 81C) of the planetary gear mechanism 81 will be described. Fig.23 : This is a cross-sectional view of the planetary gear mechanism 81 as viewed from the power source side. The planetary gear carrier 81A, the sun gear 81B, and the ring gear 81C are concentrically arranged. That is, the central axis S (rotational center axis) of the planetary gear carrier 81A, the sun gear 81B, and the ring gear 81C are consistent. The planetary gear 81D is arranged in a manner in contact with the outer periphery of the sun gear 81B and the inner periphery of the ring gear 81C. The planetary gear 81D meshes with the sun gear 81B and the ring gear 81C. The planetary gear carrier 81A, the sun gear 81B, and the ring gear 81C are supported by the housing of the planetary continuously variable transmission mechanism 24 in a manner that allows the meshing of the respective gears to be established, and can rotate around the central axis S as the center, and cannot move in other directions. The planetary gear 81D is supported by the planetary gear carrier 81A in a manner that can rotate around the rotation axis Sp as the central axis of the planetary gear 81D as the center, and cannot move in other directions. The planetary gear 81D revolves around the central axis S of the planetary carrier 81A while rotating around the central axis Sp of the planetary gear 81D.

[0236] like Fig.23 As shown in FIG. 1 , the constraint condition of the planetary gear mechanism 81 is that the sun gear 81B, the ring gear 81C and the planetary gear 81D need to be meshed. In addition, in order to ensure the strength of the gear, the diameter of the planetary gear 81D needs to be increased. That is, the constraint condition of the planetary gear mechanism 81 is that the meshing radius rs of the sun gear 81B is much smaller than the meshing radius rr of the ring gear 81C.

[0237] The structure of "No2-A" in Table 6 is that the planetary gear carrier 81A is connected to the second connecting member 31 connected to the engine 9 (power source). Therefore, the torque Tc of the planetary gear carrier 81A is the torque that the engine 9 can generate. The sun gear 81B is connected to the first connecting member 30 connected to the first transmission 33. Therefore, the torque Ts of the sun gear 81B is the torque that the first transmission 33 can generate. The ring gear 81C is connected to the third connecting member 32 connected to the idler element 28. Therefore, the torque Tr of the ring gear 81C is the torque reaction force received from the idler gear 28B.

[0238] The structure of "No2-B" in Table 6 is that the ring gear 81C is connected to the second connecting member 31. Therefore, the torque Tr of the ring gear 81C is the torque that the engine 9 can generate. The planetary gear carrier 81A is connected to the first connecting member 30. Therefore, the torque Tc of the planetary gear carrier 81A is the torque that the first transmission 33 can generate. The sun gear 81B is connected to the third connecting member 32. Therefore, the torque Ts of the sun gear 81B is the torque reaction force received from the idler gear 28B.

[0239] The configuration of "No2-C" in Table 6 is such that the planetary gear carrier 81A is connected to the second connecting member 31, the ring gear 81C is connected to the first connecting member 30, and the sun gear 81B is connected to the third connecting member 32. The configuration of "No2-D" in Table 6 is such that the ring gear 81C is connected to the second connecting member 31, the sun gear 81B is connected to the first connecting member 30, and the planetary gear carrier 81A is connected to the third connecting member 32. The configuration of "No2-E" in Table 6 is such that the sun gear 81B is connected to the second connecting member 31, the ring gear 81C is connected to the first connecting member 30, and the planetary gear carrier 81A is connected to the third connecting member 32. The configuration of "No2-F" in Table 6 is such that the sun gear 81B is connected to the second connecting member 31, the planetary gear carrier 81A is connected to the first connecting member 30, and the ring gear 81C is connected to the third connecting member 32.

[0240] Next, the relationship between the torque Ts of the sun gear 81B, the torque Tr of the ring gear 81C, and the torque Tc of the planetary gear carrier 81A is described. The sun gear 81B and the ring gear 81C are meshed via the planetary gear 81D. Therefore, the meshing tangential force between the sun gear 81B and the planetary gear 81D is equal to the meshing tangential force between the planetary gear 81D and the ring gear 81C. That is, the following equations 16 and 17 can be obtained.

[0241] [Formula 16]

[0242] Ts=rs / (rs+rr)×Tc

[0243] [Formula 17]

[0244] Tr=rr / (rs+rr)×Tc

[0245] According to the relationship between action and reaction, the following equation 18 can be obtained.

[0246] [Formula 18]

[0247] Tc=Ts+Tr

[0248] According to Formulas 16, 17, and 18, the torque Ts of the sun gear 81B, the torque Tr of the ring gear 81C, and the torque Tc of the planetary gear carrier 81A can be calculated by the meshing radius rr of the ring gear 81C and the meshing radius rs of the sun gear 81B. The meshing radius rr of the ring gear 81C and the meshing radius rs of the sun gear 81B are determined by the meshing radius of their respective gears, and thus cannot be changed during the power transmission of the planetary continuously variable transmission mechanism 24. Therefore, the ratio of the torque Ts of the sun gear 81B, the torque Tr of the ring gear 81C, and the torque Tc of the planetary gear carrier 81A remains unchanged during the power transmission of the planetary continuously variable transmission mechanism 24.

[0249] Based on this law, the controller 25 outputs a signal for controlling the first transmission 33, thereby controlling the torque of the first connection member 30 (e.g., the sun gear 81B) connected to the first transmission 33. That is, the controller 25 controls the torque of the first connection member 30 (e.g., the sun gear 81B) by controlling the first transmission 33. Thus, the controller 25 indirectly controls the torque of the second connection member 31 (e.g., the planetary gear carrier 81A) connected to the engine 9 and the torque of the third connection member 32 (e.g., the ring gear 81C) connected to the inert element 28. As a result, the transmission torque can be controlled between the second connection member 31 (e.g., the planetary gear carrier 81A) connected to the engine 9 and the third connection member 32 (e.g., the ring gear 81C) connected to the inert element 28.

[0250] Next, the relationship between the rotation speed of the sun gear 81B, the rotation speed of the ring gear 81C, and the rotation speed of the planetary gear carrier 81A is explained. First, the sun gear 81B and the ring gear 81C are meshed via the planetary gear 81D. The sun gear 81B and the ring gear 81C rotate around the center axis S. The planetary gear 81D rotates freely in the rotation direction through the planetary gear carrier 81A, and is constrained in the revolution direction relative to the center axis S of the planetary gear carrier 29A. If the relationship between the rotation speeds is calculated based on these, the following formula 19 holds. In addition, "Kb" in formula 19 is the same as formula 20. In addition, the rotation speed of the planetary gear carrier 81A is set to "Vc", the rotation speed of the sun gear 81B is set to "Vs", and the rotation speed of the ring gear 81C is set to "Vr".

[0251] [Formula 19]

[0252] Vr / Vc=-Kb{Vs / Vc}+(Kb+1)

[0253] [Formula 20]

[0254] Kb=(rs / rr)

[0255] Fig.24 The relationship between the rotation speeds of the planetary gear mechanism 81 is shown. Fig.24 The speed relationship line Y2 in Formula 19 is represented by a line graph. It is assumed that the rotation speed of the planetary gear carrier 81A is fixed. In this case, if the rotation speed of the ring gear 81C becomes higher, the rotation speed of the sun gear 81B becomes lower. Conversely, if the rotation speed of the ring gear 81C becomes lower, the rotation speed of the sun gear 81B becomes higher. Based on this law, the controller 25 outputs a signal to control the first transmission 33 to control the rotation speed of the first connecting member 30 (for example, the sun gear 81B) connected to the first transmission 33. That is, the controller 25 controls the rotation speed of the first connecting member 30 (for example, the sun gear 81B) by controlling the first transmission 33. Thus, the controller 25 indirectly controls the rotation speed of the second connecting member 31 (for example, the planetary gear carrier 81A) connected to the engine 9 and the rotation speed of the third connecting member 32 (for example, the ring gear 81C) connected to the inert element 28. As a result, the speed ratio can be controlled between the second connection member 31 (for example, the planetary carrier 81A) connected to the engine 9 and the third connection member 32 (for example, the ring gear 81C) connected to the inert element 28 .

[0256] As described above, the planetary gear mechanism 81 needs to mesh the sun gear 81B, the ring gear 81C, and the planetary gear 81D. In addition, in order to ensure the strength of the gear, the diameter of the planetary gear 81D needs to be increased. However, if the diameter of the planetary gear 81D is increased, the planetary gear mechanism 81 will be enlarged. That is, the structural constraint of the planetary gear mechanism 81 is that if the planetary gear mechanism 81 is to be designed to be small, the meshing radius rs of the sun gear 81B will be significantly smaller than the meshing radius rr of the ring gear 81C. Therefore, the planetary gear mechanism 81 has the possibility of being difficult to make the Kb value larger than 0.3 and excessively smaller than the ideal Kb value.

[0257] According to the constraints of this structure, the planetary gear mechanism 81 adjusts the meshing radius rs of the sun gear 81B and the meshing radius rr of the ring gear 81C according to the torque that can be absorbed by the first transmission 33 and the maximum allowable rotation speed from the relationship between the torque Tc, Ts, Tr (Formula 16, Formula 17, Formula 18) and the relationship between the rotation speed Vs, Vr, Vc (Formula 19, Formula 20). Thus, the Kb value of Formula 20 is set to an ideal value, and Fig.24 The inclination of the speed relationship line Y2 shown is set to an ideal value, thereby reducing both the torque that can be absorbed by the first transmission 33 and the maximum allowable rotational speed. However, if this is done, the Kb value becomes too small and it is difficult to achieve both at the same time. That is, compared with the first embodiment, the second embodiment may be disadvantageous in providing an arrangement of the planetary gear mechanism 81 that optimizes both the torque that can be absorbed by the first transmission 33 and the maximum allowable rotational speed. That is, compared with the first embodiment, the second embodiment has a tendency to make the first transmission 33 expensive, and there is a possibility that the transmission efficiency of the planetary continuously variable transmission mechanism 24 is reduced.

[0258] In addition, the size and price of the first transmission 33 are proportional to the size of the torque that can be absorbed. Therefore, it is desirable that the absorption torque of the first transmission 33 is smaller. A specific example is given in the second embodiment (i.e., No2-A in Table 6) to illustrate. First, it is desirable to reduce the Kb value of formula 20. In addition, the smaller the torque allocated to the first transmission 33, the more the transmission efficiency of the planetary continuously variable transmission mechanism 24 can be improved. Therefore, reducing the Kb value of formula 20 is beneficial for the planetary continuously variable transmission mechanism 24.

[0259] On the other hand, if Fig.24 If the Kb value is reduced in the speed relationship line Y2 shown in FIG. 1 , the rotation speed of the first transmission 33 will increase. Therefore, it is desired that the Kb value be reduced within a range that does not exceed the maximum rotation speed that the first transmission 33 can allow. The planetary gear mechanism 81 composed of the sun gear, the ring gear and the planetary gear frame has the following structural constraints, that is, if the planetary gear mechanism 81 is designed to be small, the meshing radius rs of the sun gear 81B is significantly smaller than the meshing radius rr of the ring gear 81C. Therefore, if the planetary gear mechanism 81 is designed to be small, the Kb value becomes too small. As a result, there is a possibility that the rotation speed of the first transmission 33 becomes high and exceeds the maximum allowable rotation speed of the first transmission 33. Therefore, a planetary gear mechanism 81 that can be driven at high rotation becomes necessary. That is, there is the possibility that the first transmission 33 is an expensive device corresponding to high rotation, the planetary gear mechanism 81 is a large device, and the transmission efficiency of the planetary continuously variable transmission mechanism 24 is reduced.

[0260] Next, the planetary gear mechanism 29 of the first embodiment and the planetary gear mechanism 81 of the second embodiment are compared. That is, the two planetary gear mechanisms 29 and 81 each have their own characteristics, and it is impossible to assert which one is better in general. That is, in the case where the torque that can be absorbed by the first transmission 33 and the maximum allowable rotation speed of the first transmission 33 can be freely set, it is preferred to adopt a planetary gear mechanism 81 with a simple structure. Thus, by designing the first transmission 33 in coordination with the structural constraints (Kb value) of the meshing radius rs of the sun gear 81B of the planetary gear mechanism 81 and the meshing radius rr of the ring gear 81C, a small and inexpensive first transmission 33 can be used. As a result, the planetary gear mechanism 81 can be made simple and the transmission efficiency of the planetary continuously variable transmission mechanism 24 can be improved.

[0261] On the other hand, when the torque that can be absorbed by the first transmission 33 and the maximum permissible rotation speed cannot be freely set, the planetary gear mechanism 29 of the first embodiment is preferably used. In this case, it is desirable to set the Ka value to an ideal value. Figure 7 The inclination of the speed relationship line Y1 shown is set to an ideal value, thereby fully utilizing the torque that can be absorbed by the first transmission 33 and the maximum allowable rotation speed. This allows the use of a small and inexpensive first transmission 33 and improves the transmission efficiency of the planetary continuously variable transmission mechanism 24.

[0262] Next, the internal lock speed ratio In of the planetary continuously variable transmission mechanism 24 of the second embodiment is described. When the internal lock is in operation, the rotation speed of the first connecting member 30 connected to the first transmission 33 is substituted as 0 into the above-mentioned formula 19, thereby calculating the internal lock speed ratio In. For example, in the second embodiment (No. 2-A in Table 6), the rotation speed Vs of the sun gear 81B connected to the first connecting member 30 is substituted as 0 into the formula 19. That is, the internal lock speed ratio In is the following formula 21.

[0263] [Formula 21]

[0264] Vr / Vc=Kb+1

[0265] thus

[0266] In=Kb+1

[0267] Fig.25 In the seventh modification (No. 2-B in Table 6), Expression 19 is modified and the rotation speed Vc of the planetary carrier 81A connected to the first coupling member 30 is substituted as 0. That is, the internal lock-up speed ratio In is expressed by Expression 22 below.

[0268] [Formula 22]

[0269]

[0270] thus

[0271]

[0272] Fig.26 In the eighth modification (No. 2-C in Table 6) shown, the rotation speed Vr of the ring gear 81C connected to the first coupling member 30 is substituted into Formula 19 as 0, that is, the internal lock-up speed ratio In is obtained as shown in Formula 23 below.

[0273] [Formula 23]

[0274]

[0275] thus

[0276]

[0277] Fig. 27 In the ninth modification (No. 2-D in Table 6) shown, the rotation speed Vs of the sun gear 81B connected to the first coupling member 30 is substituted as 0 in Formula 19. That is, the internal lock-up speed ratio In is given by Formula 24 below.

[0278] [Formula 24]

[0279]

[0280] thus

[0281]

[0282] Fig.28 In the tenth modification (No. 2-E in Table 6) shown, the rotation speed Vr of the ring gear 81C connected to the first coupling member 30 is substituted into Formula 19 as 0. That is, the internal lock-up speed ratio In is given by Formula 25 below.

[0283] [Formula 25]

[0284]

[0285] thus

[0286]

[0287] Fig.29 In the eleventh modified example (No. 2-F in Table 6), Expression 19 is modified and the rotation speed Vc of the planetary carrier 81A connected to the first coupling member 30 is substituted as 0. That is, the internal lock-up speed ratio In is expressed by Expression 26 below.

[0288] [Formula 26]

[0289] Vr / Vs=-Kb

[0290] thus

[0291] In=Vr / Vs=-Nb

[0292] As described above, the internal lock-up speed ratio In of the planetary continuously variable transmission mechanism 24 of the second embodiment depends on the combination of the gears of the planetary gear mechanism 81 and Kb.

[0293] As described above, according to the second embodiment, the speed change device 21 includes the input shaft 22 (input member), the output shaft 23 (output member), the planetary gear mechanism 81 (planetary mechanism), the first transmission 33, the second transmission 34, and the controller 25. The planetary gear mechanism 81 is composed of the following three components (rotating components): a planetary gear carrier 81A, a sun gear 81B (sun gear component) that rotates around the rotation center axis of the planetary gear carrier 81A, and a ring gear 81C (ring component) that is located radially outward from the sun gear 81B and rotates around the rotation center axis of the planetary gear carrier 81A.

[0294] In this case, for example, Fig.21 as well as Fig. 22 As shown, the planetary gear carrier 81A, which is one of the three components and is the first component, is connected to the input shaft 22 via the second connecting member 31 (another component). The sun gear 81B, which is the second component other than the planetary gear carrier 81A, is connected to the first transmission 33 via the first connecting member 30 and the second clutch 36 (all other components). The ring gear 81C, which is the third component other than the planetary gear carrier 81A and the sun gear 81B, is connected to the output shaft 23 via the third connecting member 32, the inert element 28, and the multi-speed change mechanism 26 (all other components). In addition, the planetary gear carrier 81A (the first component) may be directly connected to the input shaft 22. The sun gear 81B (the second component) may be directly connected to the first transmission 33. The ring gear 81C (the third component) may be directly connected to the output shaft 23.

[0295] Here, the planetary gear carrier 81A supports a planetary gear 81D (planetary component) that transmits power while rotating with the sun gear 81B and the ring gear 81C while revolving around the rotation center axis S of the planetary gear carrier 81A. In addition, the planetary gear mechanism 81 distributes the torque transmitted from the engine 9 to the planetary gear carrier 81A (first component) of the planetary gear mechanism 81 to the sun gear 81B (second component) and the ring gear 81C (third component). The planetary gear mechanism 81 performs a rotational motion with two degrees of freedom between the planetary gear carrier 81A, the sun gear 81B and the ring gear 81C. The second transmission 34 transmits the power transmitted from the first transmission 33 to the load (output shaft 23) or the power source (input shaft 22), or transmits the power transmitted from the load (output shaft 23) or the power source (input shaft 22) to the first transmission 33. Furthermore, the controller 25 changes the rotation speed of the output shaft 23 relative to the rotation speed of the input shaft 22 by changing the rotation speed of the first transmission 33 .

[0296] That is, the speed change device 21 of the second embodiment performs stepless speed change by the planetary gear mechanism 81, and transmits the power from the power source (input shaft 22) to the load (output shaft 23), or transmits the power from the load (output shaft 23) to the power source (input shaft 22). In this case, the speed change device 21 includes the planetary gear mechanism 81 provided between the input shaft 22 and the output shaft 23, the first transmission 33 connected to the planetary gear mechanism 81, and the second transmission 34 that transmits the power transmitted from the first transmission 33 to the load or the power source. In addition, the planetary gear mechanism 81 includes a planetary gear carrier 29A connected to the input shaft 22 and supporting a planetary gear 81D, a sun gear 81B connected to the first transmission 33, and a ring gear 81C connected to the output shaft 23 via the inert element 28 and the multi-speed change mechanism 26. In addition, the speed change device 21 has at least one of internal locking and external locking (direct coupling mechanism 27). Furthermore, the speed change device 21 can switch between power transmission by the planetary continuously variable transmission mechanism 24 and power transmission by locking. Therefore, the second embodiment can also achieve the same operation and effect as the first embodiment.

[0297] According to the second embodiment, similarly to the first embodiment, the transmission device 21 has two power transmission paths, namely, the first power transmission path (planetary continuously variable transmission mechanism 24) and the second power transmission path (direct coupling mechanism 27). Thus, for example, the transmission efficiency can be improved compared to a configuration in which only internal locking is performed.

[0298] According to the second embodiment, similarly to the first embodiment, the controller 25 stops the rotation of the sun gear 81B (second component) of the planetary gear mechanism 81 to achieve an internal locked state. In this case, the controller 25 outputs a command to the first transmission 33 to set the rotation speed to 0. Or the controller 25 outputs a command to stop the rotation of the component connected to the first transmission 33 by mechanical coupling. Or the controller 25 outputs a command to cut off the power transmitted from the first transmission 33 to the second transmission 34. Thus, the controller 25 stops the rotation of the sun gear 81B. In any case, internal locking can be achieved by stopping the rotation of the sun gear 81B of the planetary gear mechanism 81, which can improve the transmission efficiency.

[0299] According to the second embodiment, the lock-up rotation speed ratio is greater than the synchronization rotation speed ratio as in the first embodiment. Therefore, when power is transmitted through the second power transmission path (direct coupling mechanism 27) as the external lock mechanism, the speed can be increased.

[0300] According to the second embodiment, similarly to the first embodiment, the controller 25 releases the second clutch 36 when the vehicle stops. Therefore, when the vehicle speed is 0, the power transmission to the first transmission can be prevented.

[0301] According to the second embodiment, similarly to the first embodiment, the controller 25 engages the second clutch 36 to stop the sun gear 81B (second member) and releases the third clutch 37. Therefore, when the internal lock is performed, the power transmission to the second transmission 34 can be prevented.

[0302] According to the second embodiment, similarly to the first embodiment, when the first clutch 27C is connected, the controller 25 releases at least one of the second clutch 36 and the third clutch 37. Therefore, when the external lock is performed, the power transmission to at least one of the first transmission 33 and the second transmission 34 can be prevented.

[0303] According to the second embodiment, similarly to the first embodiment, the transmission 21 is provided with a multi-speed transmission mechanism 26 serving as a sub-speed transmission mechanism between the ring gear 81C (third member) and the output shaft 23 (output member). Therefore, the transmission 21 can reverse the rotation direction of the load (output shaft 23).

[0304] According to the second embodiment, similarly to the first embodiment, the second transmission 34 is connected to the inertial element 28 (specifically, the idler gear 28B as a rotating element) provided between the planetary gear mechanism 81 and the multi-speed change mechanism 26. Figures 30 to 39As shown, the second transmission 34 can also be configured to be connected to the following elements, including a rotating element provided between the input shaft 22 (input component) and the drive source (engine 9), a rotating element constituting the multi-speed transmission mechanism 26, a rotating element provided between the multi-speed transmission mechanism 26 and the output shaft 23 (output component), the output shaft 23 (output component), or a rotating element provided between the output shaft 23 and the load.

[0305] That is, in the first embodiment and the second embodiment, the second transmission 34 is connected to the output shaft 23 (output member) side more than the planetary gear mechanism 29, that is, the second transmission 34 is connected between the planetary gear mechanism 29 and the output shaft 23. Fig.30 The 12th modification is shown. In the 12th modification, the second transmission 34 is connected to the input gear 27A of the direct-connection mechanism 27 provided on the input shaft 22. That is, the second transmission 34 is connected between the planetary gear mechanism 29 and the input shaft 22 (input member). In this way, the second transmission 34 can be configured to be connected to the engine 9 side (drive source side) more than the planetary gear mechanism 29. In addition, although omitted in the figure, the second transmission 34 can also be connected to the lock gear 27B of the direct-connection mechanism 27.

[0306] Fig.31 A thirteenth modified example is shown. In the thirteenth modified example, the second transmission 34 is connected to the third connection member 32 connected to the inert element 28 . Fig.32 The 14th modification is shown. In the 14th modification, the second transmission 34 is connected to the odd-numbered gear 55 of the multi-speed change mechanism 26. Although not shown, the second transmission 34 may be connected to the even-numbered gear 62 of the multi-speed change mechanism 26. Fig.33 A fifteenth modification is shown. In the fifteenth modification, the second transmission 34 and the first forward speed gear 56 of the multi-speed change mechanism 26 are connected. Fig.34 In the sixteenth modified example, the second transmission 34 is connected to the third forward speed gear 57 of the multi-speed change mechanism 26 . Fig.35 In the seventeenth modified example, the second transmission 34 is connected to the second forward speed gear 63 of the multi-speed change mechanism 26 . Fig.36 In the eighteenth modified example, the second transmission 34 is connected to the fourth forward speed gear 64 of the multi-speed change mechanism 26 . Fig.37 The nineteenth modification is shown, in which the second transmission 34 is connected to the first reverse gear 65 of the multi-speed change mechanism 26. Although not shown in the figure, the second transmission 34 may be connected to the counter gear 54 of the multi-speed change mechanism 26.

[0307] Fig.38The 20th modification is shown, and the second transmission 34 is connected to the output shaft 53 (the output shaft 23 of the transmission 21) of the multi-speed transmission mechanism 26. In addition, although not shown in the figure, the second transmission 34 may be connected to the 1st speed output gear 71, the 2nd speed output gear 72, the 3rd speed output gear 73, the 4th speed output gear 74 or the reverse 1st speed output gear 75 of the multi-speed transmission mechanism 26. Fig.39 In the 21st modification, the second transmission 34 is connected to the load side (front axle 12 side, rear axle 13 side) more than the output shaft 23 of the transmission 21. In addition, although not shown in the figure, the second transmission 34 may be connected to the front axle 12, the rear axle 13, the front transmission shaft 14, or the rear transmission shaft 15. According to these modifications, for example Figure 33 to Figure 39 In the fifteenth to twenty-first modified examples shown, the second transmission 34 is connected to the output shaft 53 side rather than the idler gear 28B, so that the idler element 28 (idler gear 28B) and the multi-speed change mechanism 26 can be made small. Thus, the speed change device 21 can be manufactured at low cost.

[0308] In addition, in the first embodiment, the transmission device 21 having the multi-speed transmission mechanism 26 is described. However, it is not limited to this, and the multi-speed transmission mechanism 26 may be omitted from the transmission device 21. In this case, for example, by screwing the output gear of the output shaft 23 with the third connecting member 32, the planetary gear mechanism 29 of the planetary continuously variable transmission mechanism 24 can be connected to the output shaft 23 (output member). In addition, in this case, the second transmission 34 can be connected to the output shaft 23 side (output member side) more than the planetary gear mechanism 29, and can also be connected to the input shaft 22 side (input member side) more than the planetary gear mechanism 29. Moreover, in the first embodiment, the transmission device 21 having the direct connection mechanism 27 as the external locking mechanism is described as an example, but the direct connection mechanism 27 may also be omitted. These situations are also the same for the second embodiment and each modified example.

[0309] In the first embodiment, the case where the speed change device 21 is mounted on the wheel loader 1 is described as an example. However, it is not limited to this, and the speed change device 21 can be mounted on a work vehicle (construction machinery) other than a wheel loader such as a hydraulic excavator, a hydraulic crane, a dump truck, and a forklift. In addition, it is not limited to work vehicles, and it can also be widely used as a speed change device assembled to various vehicles such as automobiles and railway vehicles, or various industrial machinery and general machinery. This application is also the same for the second embodiment and each modified example.

[0310] In addition, each of the above-mentioned embodiments and each of the modified examples are examples, and it is of course possible to partially replace or combine the configurations shown in different embodiments and modified examples.

[0311] Description of Reference Numerals

[0312] 1 Wheel loader (working vehicle)

[0313] 21, 21A, 21B, 21C, 21D, 21E Speed ​​change device

[0314] 22 Input shaft (input component)

[0315] 23, 23A, 23B Output shaft (output component)

[0316] 24 Planetary continuously variable transmission mechanism (1st power transmission path)

[0317] 25 Controller

[0318] 26 Multi-speed transmission mechanism (auxiliary transmission mechanism, first output transmission path, second output transmission path)

[0319] 27 Direct coupling mechanism (external locking mechanism, second power transmission path)

[0320] 27C 1st clutch

[0321] 28 Inert Element

[0322] 29 Planetary gear mechanism (planetary mechanism)

[0323] 29A Planetary gear carrier (Part 1, Part 2, Part 3)

[0324] 29B 1st sun gear (1st sun gear component, 1st component, 2nd component, 3rd component)

[0325] 29C 2nd sun gear (2nd sun gear component, 1st component, 2nd component, 3rd component)

[0326] 33 1st Transmission

[0327] 34 2nd Transmission

[0328] 36 2nd Clutch

[0329] 51 Odd-numbered axis (1st output transfer path)

[0330] 52 Even-numbered axis (second output transfer path)

[0331] 58 4th clutch (1st output clutch)

[0332] 66 5th clutch (2nd output clutch)

[0333] 69 9th clutch (2nd output clutch)

[0334] 81 Planetary gear mechanism (planetary mechanism)

[0335] 81A Planetary gear carrier (Part 1, Part 2, Part 3)

[0336] 81B sun gear (sun gear member, first member, second member, third member) 81C ring gear (ring member, first member, second member, third member).

Claims

1. A speed change device, characterized in that: The invention comprises: an input shaft connected to a power source; an output shaft connected to a load; a planetary mechanism provided between the input shaft and the output shaft; a first transmission connected to the planetary mechanism; a second transmission provided separately from the first transmission; and a controller for changing the rotation speed of the first transmission, The planetary mechanism includes the following three components: a planetary gear carrier, a first sun gear component that rotates around the rotation center axis of the planetary gear carrier, and a second sun gear component that rotates around the rotation center axis of the planetary gear carrier. The first component, which is one of the three components of the planetary mechanism, is connected to the input shaft directly or via another component. A second component other than the first component among the three components of the planetary mechanism is connected to the first transmission directly or via another component. A third component other than the first component and the second component among the three components of the planetary mechanism is connected to the output shaft directly or via another component. The planetary gear carrier of the planetary mechanism supports a planetary member and a balance member that transmits power while rotating together with the first sun gear member and the second sun gear member while revolving around the rotation center axis of the planetary gear carrier. The planetary mechanism distributes the torque transmitted from the power source to the planetary mechanism to the second member and the third member. The planetary mechanism performs a rotational motion with two degrees of freedom between the first component, the second component and the third component. The second transmission transmits the power transmitted from the first transmission to the load or the power source, or transmits the power transmitted from the load or the power source to the first transmission. The controller changes the rotation speed of the output shaft relative to the rotation speed of the input shaft by changing the rotation speed of the first transmission.

2. The speed change device according to claim 1, characterized in that: The controller stops the rotation of the second component of the planetary mechanism, changes the state from performing two-degree-of-freedom rotational motion between the first component, the second component and the third component to performing single-degree-of-freedom rotational motion, and in the single-degree-of-freedom state, the power transmitted from the power source to the planetary mechanism is transmitted to the load.

3. The speed change device according to claim 1, characterized in that: When a power transmission path for transmitting power from the power source to the load via the planetary mechanism is set as a first power transmission path, a second power transmission path is provided in parallel with the first power transmission path and transmits power to the load through meshing of gears without passing through the planetary mechanism, The second power transmission path includes a first clutch that switches between engagement and release. The controller connects the first clutch to transmit power through the second power transmission path.

4. The speed change device according to claim 1, characterized in that: A second clutch is provided between the second member and the first transmission, which switches between transmission and release of power between the second member and the first transmission. The controller disconnects power transmission between the second member and the first transmission by releasing the second clutch when the vehicle stops.

5. The speed change device according to claim 1, characterized in that: Between the third member and the output shaft, there are provided a first output transmission path in which the number of meshing of the gears therebetween is an odd number, and a second output transmission path in which the number of meshing of the gears therebetween is zero or even number. The first output transmission path includes a first output clutch for switching between transmission and release of power of the first output transmission path. The second output transmission path includes a second output clutch for switching between transmission and release of power of the second output transmission path. The controller reverses the traveling direction of the vehicle by switching between a forward rotation mode in which the first output clutch is connected and the second output clutch is released and a reverse rotation mode in which the first output clutch is released and the second output clutch is connected.

6. A speed change device, characterized in that: The invention comprises: an input shaft connected to a power source; an output shaft connected to a load; a planetary mechanism provided between the input shaft and the output shaft; a first transmission connected to the planetary mechanism; a second transmission provided separately from the first transmission; and a controller for changing the rotation speed of the first transmission, The planetary mechanism includes the following three components: a planetary gear carrier, a sun gear component that rotates around the rotation center axis of the planetary gear carrier, and an annular component that is located radially outward from the sun gear component and rotates around the rotation center axis of the planetary gear carrier. The first component, which is one of the three components of the planetary mechanism, is connected to the input shaft directly or via another component. A second component other than the first component among the three components of the planetary mechanism is connected to the first transmission directly or via another component. A third component other than the first component and the second component among the three components of the planetary mechanism is connected to the output shaft directly or via another component. The planetary gear carrier of the planetary mechanism supports a planetary member that transmits power while rotating together with the sun gear member and the annular member while revolving around the rotation center axis of the planetary gear carrier. The planetary mechanism distributes the torque transmitted from the power source to the planetary mechanism to the second member and the third member. The planetary mechanism performs a rotational motion with two degrees of freedom between the first component, the second component and the third component. The second transmission transmits the power transmitted from the first transmission to the load or the power source, or transmits the power transmitted from the load or the power source to the first transmission. The controller changes the rotation speed of the output shaft relative to the rotation speed of the input shaft by changing the rotation speed of the first transmission. Furthermore, when a power transmission path for transmitting power from the power source to the load via the planetary mechanism is set as a first power transmission path, a second power transmission path is provided in parallel with the first power transmission path and transmits power to the load via meshing of gears without passing through the planetary mechanism, The second power transmission path includes a first clutch that switches between engagement and release. The controller connects the first clutch to transmit power through the second power transmission path.

7. The speed change device according to claim 6, characterized in that: The controller stops the rotation of the second component of the planetary mechanism, changes the state from performing two-degree-of-freedom rotational motion between the first component, the second component and the third component to performing single-degree-of-freedom rotational motion, and in the single-degree-of-freedom state, the power transmitted from the power source to the planetary mechanism is transmitted to the load.

8. The speed change device according to claim 6, characterized in that: A second clutch is provided between the second member and the first transmission, which switches between transmission and release of power between the second member and the first transmission. The controller releases the second clutch when the vehicle stops.

9. The speed change device according to claim 6, characterized in that: Between the third member and the output shaft, there are provided a first output transmission path in which the number of meshing of the gears therebetween is an odd number, and a second output transmission path in which the number of meshing of the gears therebetween is zero or even number. The first output transmission path includes a first output clutch for switching between transmission and release of power of the first output transmission path. The second output transmission path includes a second output clutch for switching between transmission and release of power of the second output transmission path. The controller reverses the traveling direction of the vehicle by switching between a forward rotation mode in which the first output clutch is connected and the second output clutch is released and a reverse rotation mode in which the first output clutch is released and the second output clutch is connected.

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