A transmission with two parallel input shafts.

Abstract

Up until now, most transmissions have evolved on the assumption that the internal combustion engine they are mounted to has only one output shaft. Dual-clutch transmissions are a more advanced and mainstream type of automatic transmission today, but their structure is complex, making them difficult to maintain, and it is also difficult to secure space within the transmission for electrical components that would provide fuel-saving performance. [Solution] By having two independent clutches 3 and 4 and two independent parallel input shafts 5 and 6, the transmission mechanism is made simple and compact, and the resulting space is used to secure space for installing electrical equipment. The driving support of electrical equipment, surplus power recovery, and regenerative energy storage improve fuel efficiency. Furthermore, by enabling manufacturing using conventional methods, high reliability and strong price competitiveness are achieved. The simplicity of the mechanism also improves maintainability.

Description

Technical Field

[0001] The present invention relates to a transmission connected to an internal combustion engine.

Background Art

[0002] Currently, vehicles powered by liquid fuels such as automobiles are equipped with an internal combustion engine and a transmission combined as power. The transmission appropriately shifts the driving force of the internal combustion engine, enables operation in a wide speed range, and also plays a major role in reducing fuel consumption. The internal combustion engines connected by conventional transmissions often have a single output shaft, and the technological evolution of transmissions has been mainly carried out and improved for the form connected to the internal combustion engine having this single output shaft. This is because it has been considered natural that the best is a piston-crank mechanism with an overhead valve type having a single crankshaft. This technical trend of the internal combustion engine having a single output shaft has greatly influenced the form of the transmission.

[0003] The form of the transmission has become mainly the more convenient automatic transmission form, and those combined with the internal combustion engine via a torque converter and CVTs have been invented. All are forms premised on the fact that the output shaft of the internal combustion engine as the coupling partner has a single one. Since the torque converter has low power transmission efficiency, it is difficult to reduce fuel consumption. The CVT has disadvantages such as low durability of the belt and low limit of the driving force that can be transmitted from the belt to the pulley, and cannot be adopted for internal combustion engines with large torque. In terms of power transmission efficiency and reliability, a transmission that interrupts power with a clutch and transmits power with gears is excellent, and there is a dual clutch transmission invented in recent years focusing on its advantages, but it has a very complicated and expensive mechanism such as dividing the input shaft into two concentric shafts, setting two concentric clutches, and arranging a large transmission gear mechanism. Furthermore, in order to enhance the fuel consumption reduction performance necessary for environmental protection, it is important to arrange electrical equipment for giving the transmission an electric drive function and a regenerative power storage function, and a reasonable transmission structure is required.

[0004] In contrast to internal combustion engines with a single output shaft and an overhead valve piston-crank mechanism, opposed-piston mechanisms have been devised to achieve higher combustion efficiency by converting combustion energy into power using two opposing pistons. Since these opposed-piston mechanisms also have opposing crankshafts, it is easy to install multiple engine output shafts. Therefore, there is a need to devise a transmission that effectively connects to internal combustion engines with multiple engine output shafts, such as these opposed-piston engines. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Special Publication 2023-538869 [Patent Document 2] Patent No. 7340782 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] While dual-clutch transmissions offer excellent power transmission efficiency, their complex structure and size make it difficult to effectively integrate electrical components for electric drive and regenerative braking functions. This also results in poor maintainability and high costs. Furthermore, controlling the clutch during slow-moving traffic, such as in congestion, is extremely challenging due to its influence on temperature, clutch wear, and vehicle load.

[0007] Furthermore, the clutch structure, which installs two clutches on a single internal combustion engine output shaft, and the concentric twin-shaft design differ significantly from conventional designs, requiring specialized manufacturing methods and precise component accuracy control in their production. [Means for solving the problem]

[0008] To effectively couple with an internal combustion engine having two or more output shafts, such as a thermally efficient opposed-piston internal combustion engine, an independent clutch 3 is installed for power interruption from the internal combustion engine output shaft 1, and similarly, an independent clutch 4 is installed for power interruption from the internal combustion engine output shaft 2. Because these clutches are installed independently, they can be manufactured using the technology of products commonly manufactured today. An input shaft 5, from which power from the internal combustion engine is transmitted from clutch 3, and an input shaft 6, from which power from the internal combustion engine is transmitted from clutch 4, are installed parallel and independently. A drive gear 11 for speed change is installed on input shaft 5, which can rotate freely around input shaft 5 but whose axial movement is constrained, and a drive gear 12 for speed change is installed on input shaft 6, which can rotate freely around input shaft 6 but whose axial movement is constrained. A driven gear 13 is installed on output shaft 7 that is constantly meshed with the drive gear 11 installed on input shaft 5 at a predetermined gear ratio and rotates together with output shaft 7, and a driven gear 13 is installed on input shaft 6 that is constantly meshed with the drive gear 12 installed on input shaft 6 at a predetermined gear ratio and rotates together with output shaft 7. Since drive gear 11 is installed on input shaft 5 and drive gear 12 is installed on input shaft 6, the drive gears can be distributed. Therefore, the transmission mechanism has a simple and compact configuration. Since input shaft 5 and input shaft 6 are installed independently, a complex structure such as concentric two shafts is unnecessary.

[0009] Input shafts 5 and 6 have a sleeve 14 that rotates with the input shaft and is movable in the axial direction. The sleeve 14 moves in the axial direction by a shift fork 16 operated by a shift fork mover 15 under predetermined control and connects to a predetermined drive gear 11 or drive gear 12. The connected drive gear rotates with the input shaft on which the connected drive gear is installed, and transmits the driving force to the output shaft 7 via a driven gear 13 with which the connected drive gear is always meshed, with the drive force being changed speed. Clutch 3, clutch 4, and shift fork mover 15 operate under predetermined control so that the driving force is always transmitted to the output shaft 7 via the meshing of a pair of drive gears and driven gears. Furthermore, if smoothness is required in the coupling between the sleeve 14 and the drive gear 11 or the sleeve 14 and the drive gear 12, this can be addressed by using a widely used synchromesh mechanism. Furthermore, when considering the placement of each component along the axial direction of the input shaft, space can be used efficiently by installing the sleeve 14 on input shaft 6 around the location where the drive gear 11 is placed on input shaft 5. Similarly to the case of input shaft 6, the placement of the sleeve 14 on input shaft 5 can be used efficiently by placing it around where the drive gear 12 is located on input shaft 6. This space-efficient arrangement makes the transmission's gear shifting mechanism simple and compact. Moreover, since each gear is installed on an independent shaft, a common configuration, the manufacturing of components, transmission assembly, and maintenance are also made easier. The compact gear shifting mechanism configuration resulting from having two input shafts also contributes to securing space for electrical equipment installed to reduce fuel consumption.

[0010] An electric motor 8 is installed to apply driving force to the input shaft 5, which is fitted with a reverse drive gear 17, and a clutch 9 is installed to intermittently interrupt the driving force generated by the electric motor 8. A generator 10 is installed that generates electricity using the driving force of the input shaft 6, which is not connected to the power of the electric motor 8. In addition, a power control unit 18 that controls the amount of power generated and the motor output, a storage battery 19 for storing electricity, and a wire harness 20 for connecting electrical equipment are installed. Furthermore, the power control unit also performs predetermined controls on the operation of the internal combustion engine and the operation of clutches 3, 4, 9, and sleeve 14.

[0011] To transmit the driving force of the electric motor 8 to the output shaft 7, the electric motor 8 and the input shaft 5 are coupled by the clutch 9, and a predetermined drive gear 11 and a predetermined sleeve 14 installed on the input shaft 5 are coupled. At this time, if the transmission of driving force from the internal combustion engine to the input shaft 5 is disconnected by the clutch 3, it becomes possible to run using only the electric motor 8. The aforementioned running using only the motor 8 can also be applied to reverse running by coupling the reverse drive gear 17 and the sleeve 14, so the half-clutch state of the clutch 3 and clutch 4 at the time of starting is unnecessary, and the complex control required for smooth starting and clutch wear can be greatly reduced. Forward starting is also possible by coupling the predetermined input gear 11 and the sleeve 14 and using the power of the electric motor 8, and as with reverse running, the complex control and clutch wear can be greatly reduced.

[0012] When the driving force of the electric motor 8 is transmitted to the output shaft 7, the clutch 3 transmits the driving force from the output shaft 1 of the internal combustion engine to the input shaft 5, thereby enabling the simultaneous transmission of the driving forces of the internal combustion engine and the electric motor 8 to the output shaft 7. This drive system using the internal combustion engine and the electric motor 8 is implemented when the operating resistance increases during operation using the power of the internal combustion engine and the driving force from the internal combustion engine becomes insufficient. This allows the electric motor 8 to assist the driving force of the internal combustion engine. When the driving force from the output shaft 2 of the internal combustion engine is transmitted to the input shaft 4 by the clutch 4, the generator 10 converts the driving force from the internal combustion engine into predetermined power, and this power is supplied to the electric motor 8 and the battery 19 after predetermined adjustments are made by the power control unit. When there is surplus output from the internal combustion engine during operation, it is possible to recover the excess output as electricity and store it in the battery 19.

[0013] When the output shaft decelerates, clutches 3 and 4 are released, and a predetermined drive gear 12 and a predetermined sleeve 14 installed on the input shaft 6 are coupled. This transmits the driving force of the output shaft 7 to the generator 10, which generates electricity, and the generated electricity is regenerated and stored in the battery 19. Furthermore, the generator rotation speed during regenerative storage can be adjusted by switching to coupling different drive gears 12 and sleeves 14 installed on the input shaft 6.

[0014] During engine starting, the clutch 3 connects the internal combustion engine output shaft 1 to the input shaft 5, and the clutch 9 connects the electric motor 8 to the input shaft 5. By applying power from the battery 19 to the electric motor 8, the internal combustion engine can be started. Starting the internal combustion mechanism with the electric motor 8 eliminates the need for a starter motor. As described above, having two input shafts allows for the realization of a simple transmission mechanism and simplifies the installation of electrical equipment, resulting in a transmission that is easy to manufacture, inexpensive, and contributes to low fuel consumption. [Effects of the Invention]

[0015] Having two parallel input shafts makes the transmission's gear shifting mechanism simpler and more compact. The resulting space savings from this simpler and more compact configuration facilitate the installation of the electric motor 8 and generator 10. These electric devices assist the internal combustion engine, extending the fuel-efficient operating time of the engine and contributing to increased idle time, thereby reducing fuel consumption. This reduction in fuel consumption reduces the user's burden of purchasing expensive and valuable non-fossil fuels. Furthermore, in regions where the introduction of electric vehicles is difficult due to the ongoing development of electrical infrastructure, this product can be attractively received as an inexpensive and environmentally friendly option.

[0016] Clutch 3 and Clutch 4 are installed independently and, as with conventionally widely used structures, the design and manufacturing know-how accumulated over the years is reflected in the transmission, enabling high quality and lower cost, as well as improved maintainability.

[0017] Since input shafts 5 and 6 are independent shafts, the structure is similar to that widely used in the past, and manufacturing can be carried out using conventional methods. The design and manufacturing know-how accumulated through conventional methods is reflected in the transmission, enabling higher quality and lower costs, as well as improved maintainability. [Brief explanation of the drawing]

[0018] [Figure 1] This is a diagram illustrating the configuration of a transmission according to the present invention when the internal combustion engine output shaft 1 and the internal combustion engine output shaft 2 rotate in the same direction. (Example 1) [Figure 2] This is a diagram illustrating the configuration of a transmission according to the present invention when the internal combustion engine output shaft 1 and the internal combustion engine output shaft 2 rotate in opposite directions. (Example 2) [Figure 3] This shows the state in which the output of the internal combustion engine is transmitted to the input shaft 5 and the engine is running. (Example 3) [Figure 4] This shows the state in which the output of the internal combustion engine is transmitted to the input shaft 6 and the engine is running, and the generator 10 is generating electricity. (Example 4) [Figure 5] Shows the gear change preparation operation in gear change. (Example 5) [Figure 6] Shows the charge state when the output of the internal combustion engine is surplus. (Example 6) [Figure 7] Shows the state where the electric motor 8 is assisting in driving. (Example 7) [Figure 8] Shows the state of starting with electric power. (Example 8) [Figure 9] Shows the state of regenerative power storage. (Example 9) [Figure 10] Shows the state of reverse running with electric power. (Example 10) [Figure 11] Shows the state at the start of the internal combustion engine. (Example 11) [Figure 12] Shows an example in which the transmission of the present invention is coupled to an opposed piston internal combustion engine. (Example 12)

Mode for Carrying Out the Invention

[0019] A clutch is installed at the internal combustion engine coupling part so that assembly work and maintenance can be facilitated. When looking at the arrangement positions of the parts in the axial direction of the input shaft, the transmission mechanism can be made compact by alternately arranging the drive gears on the two input shafts. The electric motor 8 and the generator 10 are separated from the transmission mechanism part and arranged so that manufacturing and maintenance can be facilitated.

Examples

[0020] Fig. 1 is a configuration diagram of the transmission according to the present invention coupled to an internal combustion engine in which the internal combustion engine output shaft 1 and the internal combustion engine output shaft 2 rotate in the same direction. The clutches 3, 4, and 9 are in an open state and no power transmission is occurring. The sleeve 14 is in the neutral position and is not engaged with the drive gears 11 and 12. When the transmission of the present invention is mounted longitudinally in a vehicle, it is similar to this.

Examples

[0021] Figure 2 is a diagram of the configuration of a transmission according to the present invention, which is coupled to an internal combustion engine in which the internal combustion engine output shaft 1 and the internal combustion engine output shaft 2 rotate in opposite directions. Compared to the configuration in Figure 1, the rotation of the input shaft 5 and the input shaft 6 is made to be in the same direction by the reversing drive gear 21 and the reversing driven gear 22 installed inside the transmission of the clutch 4. [Examples]

[0022] Figure 3 shows the state from Figure 2 where the clutch 3 is activated, the driving force from the internal combustion engine output shaft 1 is transmitted to the input shaft 5, and the gear is shifted using the drive gear 11 installed on the input shaft 5. The white arrows indicate the clutch operation and the movement of the shift fork from the neutral position, and are also shown in other figures. [Examples]

[0023] Figure 4 shows the state from Figure 2, where the clutch 4 is activated, the driving force of the internal combustion engine output shaft 2 is transmitted to the input shaft 6 via the reversing drive gear 22 and reversing driven gear 23, the drive gear 12 installed on the input shaft 6 is used to change gears, the generator 10 generates electricity and the storage battery 19 is charged. The black arrows indicate the flow of electricity and are also shown in the other figures. [Examples]

[0024] Figure 5 shows the gear shifting preparation operation in situations where rapid gear changes are required, such as when the vehicle is running solely on internal combustion engine power. This is an example of operation from the state shown in Figure 4. The gear to be switched to is predicted by a predetermined control, and the drive gear 11 and sleeve 14 installed on the input shaft 5 are coupled. This predictive operation reduces the time required for gear shifting to only the clutch operation time. [Examples]

[0025] Figure 6 shows the case where the internal combustion engine output is in excess of the operating resistance. The driving force from the internal combustion engine output shaft 1 is shifted by the drive gear 11 installed on the input shaft 5 and transmitted to the output shaft 7. In addition, the clutch 4 is also activated, and the driving force from the internal combustion engine output shaft 2 is transmitted to the generator 10 to generate electricity. The generated electricity is adjusted by the power control unit 18 and stored in the battery 19. [Examples]

[0026] Figure 7 shows the state after switching the combination of drive gear 11 and driven gear 13, which transmit power installed on the input shaft 5, to a combination for high-speed operation, from the state in Figure 6. At the same time, clutch 9 is activated, and the electric motor 8 is supplying driving force to the input shaft 5. This alleviates the burden on the internal combustion engine in response to the increased operating resistance. Clutch 2 is also activated and the generator 10 is generating power. At this time, the power generated and the power from the storage battery 19 are adjusted by the power control unit 18 and supplied to the electric motor 8. [Examples]

[0027] Figure 8 shows the state when starting using electric power. From the state in Figure 2, clutch 9 is activated, transmitting the driving force of the electric motor 8 to the input shaft 5, and clutch 2 is activated, also generating electricity. If more driving force is needed, the drive gear is shifted down to another drive gear installed on the input shaft 5. The generator 10 is also generating electricity, and the power generated and the power from the storage battery are adjusted by the power control unit 18 and supplied to the electric motor 8. After this, when the amount of stored electricity is sufficient, clutch 4 can be released and the generator 10 can stop generating electricity. [Examples]

[0028] Figure 9 shows the regenerative power storage state. Due to the deceleration of the driven object, driving force is applied from the output shaft 7 to the transmission. This driving force is transmitted to the input shaft 6 via the drive gear 12, and the generator 10 generates electricity. The generated electricity is sent to the power control unit 18 via the wire harness 20, adjusted, and regenerated and stored in the battery 19. The rotational speed of the generator 10 can be changed by switching to other drive gears installed on the input shaft 6. [Examples]

[0029] Figure 10 shows the vehicle in reverse using electric power. The clutch 9 transmits the driving force of the electric motor 10 to the input shaft 5. This driving force is transmitted to the output shaft 7 in the opposite direction to that of forward movement via the reverse drive gear 17, idler gear 23, and driven gear 13. Electricity is supplied from the battery 19 to the electric motor 8 via the wire harness 20, after being regulated by the power control unit 18. If the stored power is insufficient, the clutch 4 is activated to generate electricity using the output of the internal combustion engine. [Examples]

[0030] Figure 11 shows the state when the internal combustion engine is started. Clutches 3 and 9 are activated to transmit the driving force of the electric motor 8 to the engine output shaft 1, causing the stationary engine output shaft 1 to rotate. Power is supplied from the storage battery 19 to the electric motor 8 via the wire harness 20, after being regulated by the power control unit 18. [Examples]

[0031] Figure 12 shows an embodiment in which the transmission of the present invention is mounted on an opposed-piston internal combustion engine. Unlike the other figures, the internal combustion engine output shaft 1 is shown at the top and the output shaft 7 is shown at the bottom, and the figure is a view from the side of the cylinder. For clarity, the valve train and intake / exhaust devices are omitted. The internal combustion engine paired with the transmission of the present invention has intake / compression cylinders 24 and expansion / exhaust cylinders 25 set separately for the purpose of improving thermal efficiency. It also has a rotating perforated cylindrical valve 26 and a combustion chamber 27 between the cylinders. Crank A31 has a crank gear A35, and crank gear A35 is constantly meshed with output gear A37 which rotates together with the internal combustion engine output shaft 1. Symmetrically arranged crank B32 has a crank gear B36, and crank gear B36 is constantly meshed with output gear B38 which rotates together with the internal combustion engine output shaft 2, and output gear B38 is constantly meshed with symmetrically arranged output gear A37. Since the engine output shaft 2 rotates in the opposite direction to the engine output shaft 1, the transmission has a counter-rotating drive gear 21 and a counter-rotating driven gear 22.

[0032] Opposed-piston internal combustion engines have excellent thermal efficiency because they can convert combustion energy into power using two pistons. The transmission of the present invention also has a gear shifting mechanism using gears with high transmission efficiency, a function to extend the fuel-saving operation state of the internal combustion engine by supplementing power with an electric motor 8 in response to fluctuations in driving resistance, and a function to store the surplus output of the internal combustion engine and regenerative energy during deceleration in a storage battery 19, thus achieving extremely high fuel-saving performance. [Industrial applicability]

[0033] This invention can be implemented as a transmission mechanism coupled to an internal combustion engine mounted on an automobile or the like. [Explanation of Symbols]

[0034] 1. Internal combustion engine output shaft 2. Internal combustion engine output shaft 3 Clutch 4 Clutch 5 Input shaft 6 Input shaft 7 Output shaft 8 Electric motor 9 Clutch 10 Generator 11 Drive gear 12 Drive gear 13 Driven Gear 14 Sleeves 15 Shift fork mover 16 Shift fork 17 Reverse drive gear 18 Power control unit 19. Battery 20. Wire harness 21 Reversing drive gear 22 Reversing driven gear 23 Idler gear 24 Intake compression cylinder 25 Expansion exhaust cylinder 26 Rotating perforated cylindrical valve 27 Combustion chamber 28 Intake compression piston 29 Expansion exhaust piston 30 Connecting rod 31 Crank A 32 Crank B 33 Intake valve 34 Exhaust valve 35 Crank gear A 36 Crank gear B 37 Output gear A 38 Output gear B

Claims

1. The internal combustion engine has two internal combustion engine output shafts, output shaft 1 and output shaft 2, which rotate in the same direction. It has a clutch 3 connected to output shaft 1 and a clutch 4 connected to output shaft 2, respectively, and has an input shaft 5 to which internal combustion engine power is transmitted from clutch 3 and an input shaft 6 to which internal combustion engine power is transmitted from clutch 4, both independently and in parallel. A drive gear 11 for speed change is installed on input shaft 5, which rotates freely around input shaft 5 and whose axial movement is restricted. A drive gear 12 for speed change is installed on input shaft 6, which rotates freely around input shaft 6 and whose axial movement is restricted. A driven gear 13 that constantly meshes with the drive gear 11 installed on input shaft 5 at a predetermined gear ratio and rotates together with output shaft 7 and a driven gear 13 that constantly meshes with the drive gear 12 installed on input shaft 6 at a predetermined gear ratio and output A transmission having two parallel input shafts, characterized by having a driven gear 13 that rotates together with shaft 7, an input shaft 5 and an input shaft 6 each having a sleeve 14 that rotates together with the input shafts and is movable in the axial direction, the sleeve 14 being moved in the axial direction by a shift fork 16 operated by a shift fork mover 15 under predetermined control and coupled with a drive gear 11 or drive gear 12, and a transmission mechanism that transmits the driving force to the output shaft 7 via a driven gear 13 that is always meshed with the coupled drive gear 11 or drive gear 12, an electric motor 8 that generates driving force on input shaft 5 where a reverse drive gear 17 is installed, a clutch 9 that intermittently intermittently transmits the driving force generated by the electric motor 8, and a generator 10 that generates electricity using the driving force of the other input shaft 6 to which the driving force from the electric motor 8 is not transmitted.

2. In coupling with an internal combustion engine whose output shaft 2 rotates in the opposite direction to the output shaft 1 of the internal combustion engine, the transmission has a reversing drive gear 21 on the transmission side of the clutch 4 that rotates together with the clutch 4, and a reversing driven gear 22 that is always meshed with the reversing drive gear 21 and rotates together with the input shaft 6, as described in claim 1, which has two parallel input shafts.

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