Transmission part structure and recombination system of transmission part structure

Abstract

To provide a transmission part structure and a recombination system of the transmission part structure, capable of restraining an increase in development manhours and the number of part items, and capable of improving maintainability.SOLUTION: The transmission part structure 1 includes an output shaft 5 connected to a wheel, a counter shaft 4 connected to the output shaft 5 via a gear, a first housing 6 provided with the output shaft 5, and a second housing 7 provided with the counter shaft 4. The second housing 7 is detachably fixed to the first housing 6.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a transmission structure and a transmission structure recombination system. [Background technology]

[0002] For example, Patent Document 1 describes a transmission structure for a vehicle in which parallel gear trains are combined. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 10,968,994 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to be able to switch the reduction ratio in the above-described transmission structure, it is necessary to provide multiple gear shafts (for example, an output shaft and a counter shaft). These gear shafts are usually provided in a single housing to form a gearbox. However, different gear ratios (sets of multiple switchable gear ratios) may be set depending on the vehicle model, etc. In this case, the gear shafts must be swapped depending on the gear ratio, and the distance between the gear shafts changes. Therefore, multiple housings (gearboxes) are required depending on the distance between the gear shafts. Developing and designing each of these gearboxes would increase the development man-hours and the number of parts. Furthermore, it is preferable for the transmission structure to be easy to maintain.

[0005] Therefore, an object of the present invention is to provide a transmission structure and a transmission structure reconfiguration system that can suppress an increase in development man-hours and the number of parts, and can improve maintainability. [Means for solving the problem]

[0006] The transmission structure of the present invention is [1] "a transmission structure comprising an output shaft connected to a wheel, a counter shaft connected to the output shaft via a gear, a first housing in which the output shaft is provided, and a second housing in which the counter shaft is provided, wherein the second housing is detachably fixed to the first housing."

[0007] In this transmission structure, the second housing, which is provided with the countershaft, is detachably fixed to the first housing, which is provided with the output shaft. This allows for changing the gear ratio combination, for example, to accommodate differences in vehicle model, by simply replacing the second housing and the countershaft (the gearbox on the countershaft side) while using the first housing and the output shaft (the gearbox on the output shaft side). This reduces the number of development steps and the number of parts. Furthermore, the second housing can be removed for maintenance and inspection to check the interior, and only the second housing and the countershaft need to be replaced rather than the entire transmission structure, improving maintainability. Therefore, this transmission structure reduces the number of development steps and the number of parts, while also improving maintainability.

[0008] The transmission structure of the present invention may be [2] "the transmission structure according to [1], further comprising a drive source that generates power for driving the wheels, the drive source being provided in the first housing." In this case, because the relatively expensive drive source is provided on the first housing side, which is not subject to replacement, costs can be reduced.

[0009] The transmission structure reassembly system of the present invention is [3] "a transmission structure reassembly system comprising the transmission structure described in [1] or [2] and another second countershaft and second housing having a gear ratio different from those of the second countershaft and second housing, wherein the other second housing can be fixed to the first housing in place of the second housing." For the reasons mentioned above, this reassembly system can suppress increases in development man-hours and number of parts, and improve maintainability. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a transmission structure and a transmission structure reconfiguration system that can suppress an increase in development man-hours and the number of parts, and can improve maintainability. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is a cross-sectional view of the transmission structure according to the embodiment. [Figure 2] FIG. 4 is a cross-sectional view showing a state in which the second housing is removed from the first housing. [Figure 3] 1A is a cross-sectional view of the transmission structure according to the embodiment, and FIG. 1B is a cross-sectional view of the transmission structure to which another second gear box is attached. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same or equivalent elements are designated by the same reference numerals, and redundant description will be omitted.

[0013] The transmission structure 1 shown in Fig. 1 is mounted on a vehicle to form a transmission. The vehicle is, for example, a commercial vehicle such as a truck or a bus, but is not limited thereto, and may be, for example, a large vehicle, a medium-sized vehicle, a standard passenger car, a small vehicle, or a light vehicle. The transmission structure 1 includes a motor 2, an input shaft 3, a countershaft 4, an output shaft 5, a first housing 6, and a second housing 7.

[0014] The motor 2 is, for example, a motor generator, and is a drive source that generates power to drive the wheels of the vehicle. The output shaft of the motor 2 is connected to the input shaft 3, and the power of the motor 2 is transmitted to the input shaft 3. The input shaft 3 is arranged parallel to the vehicle width direction. Multiple gears 3a, 3b (two in this example) are fixed to the input shaft 3. The gears 3a, 3b have different numbers of teeth and diameters, and are fixed at different positions in the longitudinal direction of the input shaft 3. The gear 3a is, for example, a first gear, and the gear 3b is a second gear with a larger number of teeth than the gear 3a. In this example, the input shaft 3 is formed in a hollow cylindrical shape, and a second portion 5b of the output shaft 5, which will be described later, is arranged inside.

[0015] The countershaft 4 is disposed, for example, forward of the input shaft 3 and the output shaft 5 in the vehicle longitudinal direction. A plurality of (two in this example) gears 4a and 4b are fixed to the countershaft 4. The gears 4a and 4b have different numbers of teeth and diameters and are fixed at different positions in the longitudinal direction of the countershaft 4 so as to mesh with the gears 3a and 3b, respectively. In other words, the gear 4a is a driven gear that rotates in conjunction with the rotation of the gear 3a, and the gear 4b is a driven gear that rotates in conjunction with the rotation of the gear 3b. In this example, the gear 4b has fewer teeth than the gear 4a.

[0016] The countershaft 4 is connected to the input shaft 3 via gears 3a, 3b, 4a, and 4b. More specifically, the connection state between the countershaft 4 and the input shaft 3 is switched between a first state in which the countershaft 4 and the input shaft 3 are connected via gears 3a and 4a, and a second state in which the countershaft 4 and the input shaft 3 are connected via gears 3b and 4b. This switching is performed by a switching mechanism 8. The switching mechanism 8 is configured, for example, to include a sleeve mechanism attached to the countershaft 4. The sleeve mechanism moves on the countershaft 4 and selectively engages with gear 4a or gear 4b, thereby switching between the first state and the second state. The countershaft 4 rotates in the opposite direction to the input shaft 3 due to the driving force transmitted from the input shaft 3. The reduction ratio in this transmission changes depending on whether the connection state between the countershaft 4 and the input shaft 3 is in the first state or the second state. In other words, in the transmission structure 1, the gears 3a, 3b, 4a, and 4b and the switching mechanism 8 constitute a transmission mechanism.

[0017] Additionally, a gear 4c is fixed to the countershaft 4. The gear 4c is, for example, a final gear, and transmits driving force from the countershaft 4 to an output shaft 5 (axle shaft). The gear 4c is in mesh with a differential gear 5c fixed to the output shaft 5. The differential gear 5c is a differential device and is made up of multiple gears.

[0018] The output shaft 5 has a first portion 5a and a second portion 5b. The first portion 5a is connected to a differential gear 5c on one side in the vehicle width direction, and the second portion 5b is connected to the differential gear 5c on the other side in the vehicle width direction. The first portion 5a and the second portion 5b are arranged coaxially and constitute a single output shaft. The second portion 5b is arranged inside the hollow input shaft 3 and is arranged coaxially with the input shaft 3. That is, in this example, the input shaft 3 and the output shaft 5 are arranged coaxially and constitute input and output shafts. The tip of the first portion 5a is connected to one wheel, and the tip of the second portion 5b is connected to the other wheel. In this example, these wheels are the wheels on the rear side of the vehicle. The output shaft 5 is rotated by driving force transmitted from the motor 2 via the input shaft 3 and the countershaft 4, thereby driving the vehicle.

[0019] The first housing 6, together with the input shaft 3 and the output shaft 5, constitutes a first gearbox 11. The first housing 6 is provided with the motor 2, the input shaft 3, and the output shaft 5. The first housing 6 has an accommodation section 6a that accommodates the motor 2 and an arrangement section 6b in which the differential gear 5c and the like are arranged. The accommodation section 6a and the arrangement section 6b are aligned in the vehicle width direction. The arrangement section 6b is open on the side facing the second housing 7 and is closed when the second housing 7 is attached to the first housing 6. The gears 3a and 3b and the differential gear 5c are arranged in the arrangement section 6b. The input shaft 3 is rotatably fixed to the accommodation section 6a via a pair of bearings 21, and the first portion 5a of the output shaft 5 is rotatably fixed to the arrangement section 6b via a bearing 22.

[0020] The second housing 7, together with the countershaft 4, constitutes a second gearbox 12. The second housing 7 is provided with the countershaft 4. The countershaft 4 is rotatably fixed to the second housing 7 via a pair of bearings 23. The gears 4a, 4b, and 4c and the switching mechanism 8 are disposed in the second housing 7. The second housing 7 is open on the side facing the first housing 6, and is closed when the first housing 6 and the second housing 7 are attached. In this attached state, the second housing 7 faces the placement portion 6b of the first housing 6 in the vehicle longitudinal direction, but does not substantially face the accommodating portion 6a. This arrangement allows the transmission structure 1 to be made compact. In this example, the second housing 7 is configured by connecting a first portion 7a disposed on the front side in the vehicle longitudinal direction to a second portion 7b disposed on the rear side by connecting members 31, such as bolts.

[0021] 1 and 2, the second housing 7 is detachably fixed to the first housing 6. In FIG. 1, the second housing 7 is attached to the first housing 6, and in FIG. 2, the second housing 7 is removed from the first housing 6. From a different perspective, the second gearbox 12 including the countershaft 4 is detachably fixed to the first gearbox 11 including the input shaft 3 and the output shaft 5. In this example, the first portion 7a of the second housing 7 is connected to the accommodating portion 6a of the first housing 6 by a connecting member 32, such as a bolt, and the first portion 7a of the second housing 7 is connected to the arrangement portion 6b of the first housing 6 by a connecting member 33, such as a bolt. In this way, the first housing 6 and the second housing 7 are detachably fixed to each other.

[0022] That is, in the transmission structure 1, a single (integral) gearbox is not provided to include the input shaft 3, countershaft 4, and output shaft 5, but the gearbox is divided into a first gearbox 11 and a second gearbox 12 in the longitudinal direction of the vehicle. The rear first gearbox 11 and the front second gearbox 12 are detachably fixed together by connecting members 32, 33.

[0023] 3 is a diagram illustrating a recombination system 100 for a transmission structure 1 according to an embodiment. The recombination system 100 further includes a second gear box 12A in addition to the transmission structure 1 described above. In the second gear box 12A, the gear ratios between the input shaft 3 and the counter shaft 4 (the gear ratio between gear 3a and gear 4a and the gear ratio between gear 3b and gear 4b) and the gear ratio between the counter shaft 4 and the output shaft 5 (the gear ratio between gear 4c and differential gear 5c) are different from those of the second gear box 12 described above. Accordingly, the diameters of the gears 4a, 4b, and 4c are different from those of the second gear box 12, and the shape of the second housing 7A of the second gear box 12A is different from that of the second gear box 12.

[0024] In the recombination system 100, the second gear box 12A (second housing 7) can be fixed to the first gear box 11 (first housing 6) instead of the second gear box 12 (second housing 7A). That is, the second gear boxes 12 and 12A are recombinable. [Action and effect]

[0025] In the transmission structure 1, the second housing 7, which is provided with the countershaft 4, is detachably fixed to the first housing 6, which is provided with the output shaft 5. As a result, when changing the gear ratio set to accommodate differences in vehicle model, for example, the first housing 6 and the output shaft 5 (first gearbox 11) can be reused while the second housing 7 and the countershaft 4 (second gearbox 12) can be swapped to accommodate the change in gear ratio set. This reduces the number of development steps and the number of parts. Furthermore, the second housing 7 can be removed for maintenance and inspection to check the interior, and only the second housing 7 and the countershaft 4 need to be replaced rather than the entire transmission structure 1, improving maintainability. Therefore, the transmission structure 1 reduces the number of development steps and the number of parts, while improving maintainability.

[0026] The motor 2 (drive source) that generates power to drive the wheels is provided in the first housing 6. This allows for cost reduction because the relatively expensive motor 2 is provided on the first housing 6 (first gear box 11) side, which is not subject to replacement.

[0027] In the recombination system 100, instead of the second housing 7 (second gear box 12), another second housing 7A (second gear box 12A) having a different gear ratio can be fixed to the first housing 6 (first gear box 11). For the reasons described above, the recombination system 100 can suppress an increase in the number of development steps and parts, and can also improve maintainability.

[0028] The present invention is not limited to the above-described embodiment and modifications. For example, the materials and shapes of the components are not limited to those described above, and various materials and shapes can be adopted.

[0029] The motor 2 (drive source) does not have to be provided in the first housing 6, but may be provided in the second housing 7, for example, or may be provided separately from the first housing 6 and the second housing 7. A vehicle equipped with the transmission structure 1 may have an engine as a drive source, or may be a hybrid vehicle equipped with both a motor and an engine. Note that if an attempt is made to accommodate not only cases where an engine is used as a drive source but also cases where a motor is used as a drive source, the number of gear ratio combinations will increase even further. The transmission structure 1 can be suitably used in such cases. [Explanation of symbols]

[0030] 1...transmission unit structure, 2...motor (drive source), 3a, 3b, 4a, 4b, 4c...gears, 4...counter shaft, 5...output shaft, 6...first housing, 7, 7A...second housing, 100...recombination system

Claims

1. an output shaft connected to the wheels; a counter shaft connected to the output shaft via a gear; a first housing in which the output shaft is provided; a second housing in which the counter shaft is provided, The second housing is detachably fixed to the first housing.

2. a drive source that generates power for driving the wheels; The transmission structure according to claim 1 , wherein the drive source is provided in the first housing.

3. The transmission structure according to claim 1 or 2; a counter shaft and a second housing having a gear ratio different from those of the counter shaft and the second housing, A transmission structure reconfiguration system in which the other second housing can be fixed to the first housing in place of the second housing.

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