Transmission system, and construction machine comprising transmission system

Abstract

The present invention relates to a transmission system, and construction machinery comprising the transmission system. The transmission system comprises a box body and a transmission mechanism accommodated in the box body, wherein the transmission mechanism comprises a power input shaft, a planetary gear mechanism and an output shaft, the transmission mechanism further comprises a gear shifting mechanism, the gear shifting mechanism being configured to be selectively engaged with a first output gear or a second output gear; when the gear shifting mechanism is engaged with the first output gear, power is transmitted to the output shaft via the planetary gear mechanism, in which case the transmission mechanism is in first gear; and when the gear shifting mechanism is engaged with the second output gear, power is transmitted to the output shaft bypassing the planetary gear mechanism, in which case the transmission mechanism is in second gear. By using the transmission system of the present invention, a structure is simple, a layout is compact, maintenance is more convenient, and the cost is lower.

Description

Speed ​​change system and engineering machinery including the same Technical Field

[0001] The present invention relates to the field of engineering machinery, in particular to the technical field of transmissions used in engineering machinery, and specifically to a speed change system and engineering machinery comprising the speed change system. Background Art

[0002] In construction machinery, especially wheeled construction machinery, in order to adapt to different operating conditions, it is often necessary to configure a speed change system to achieve speed change and shifting, thereby outputting different speeds and torques for different working conditions.

[0003] For example, various two-speed planetary transmissions are known in the prior art, utilizing the engagement and disengagement of clutches and brakes to shift and adjust between gears. However, these known planetary transmissions experience high frictional heat generation from the friction plates at the moment of brake or clutch engagement, leading to rapid wear of the friction plates. This shortens the transmission's lifespan and increases maintenance costs, making maintenance frequent and costly. In particular, when high-speed motors are used, the planetary gear train's moment of inertia is high, and the transmission's bulk increases, resulting in low vehicle space utilization.

[0004] In addition, conventional two-speed gearboxes are also known in the prior art. Since this type of gearbox does not use a planetary gear mechanism, in order to obtain a large transmission ratio, it is often necessary to set up multiple gears, resulting in more transmission components, low utilization of the internal space of the gearbox, and occupying a large space in the entire vehicle.

[0005] Therefore, it is necessary to propose a transmission system with compact structure, easier maintenance and lower cost.

[0006] Summary of the Invention

[0007] The object of the present invention is to solve at least one of the above problems and / or other problems existing in the prior art.

[0008] To achieve the above-mentioned purpose, according to one aspect of the present invention, a speed change system is proposed, which includes a case and a speed change mechanism accommodated in the case, the speed change mechanism including a power input shaft, a planetary gear mechanism and an output shaft, and a first output gear and a second output gear are installed on the output shaft, the speed change mechanism also includes a shift mechanism, and the shift mechanism is configured to be able to selectively engage with the first output gear or the second output gear; wherein, when the shift mechanism is engaged with the first output gear, power is transmitted from the power input shaft to the output shaft through the planetary gear mechanism through the first output gear engaged with each other and the shift mechanism, and at this time the speed change mechanism is in first gear, and when the shift mechanism is engaged with the second output gear, power is transmitted from the power input shaft to the output shaft through the second output gear engaged with each other and the shift mechanism without passing through the planetary gear mechanism, and at this time the speed change mechanism is in second gear.

[0009] According to an embodiment of the present invention, the power input shaft and the output shaft are arranged in parallel with each other and spaced apart from each other.

[0010] According to one embodiment of the present invention, the planetary gear mechanism includes a sun gear fixedly connected to the power input shaft, a planetary carrier, a plurality of planetary gears mounted on the planetary carrier and meshing with the sun gear, and a ring gear meshing with the plurality of planetary gears, and the ring gear is fixed to the housing.

[0011] According to one embodiment of the present invention, the speed change mechanism further includes an input gear non-rotatably connected to the power input shaft, and the input gear is engaged with the second output gear; the speed change mechanism further includes an intermediate gear non-rotatably connected to the planetary carrier, and the intermediate gear is engaged with the first output gear.

[0012] According to an embodiment of the present invention, the intermediate gear is arranged on a first side of the sun gear, and the input gear is arranged on a second side of the sun gear opposite to the first side.

[0013] According to one embodiment of the present invention, the sun gear and the power input shaft are formed as an integral piece.

[0014] According to an embodiment of the present invention, the shift mechanism includes a shift sleeve and a shift fork, and the shift fork can be actuated to move the shift sleeve to engage with the first output gear or the second output gear.

[0015] According to one embodiment of the present invention, external splines are provided on the outer peripheries of the central hubs of the first output gear and the second output gear, and internal splines engageable with the external splines are provided on the inner periphery of the shift sleeve.

[0016] According to another aspect of the present invention, there is further provided an engineering machine, which includes the speed change system as described above.

[0017] According to an embodiment of the present invention, the output shaft of the speed change mechanism is connected to a drive axle of the engineering machine, and the drive axle is connected to wheels via half shafts.

[0018] According to the transmission system of the present invention, a large transmission ratio is achieved by adopting a planetary gear mechanism, thereby reducing the intermediate shaft and its gears, thereby reducing the height space of the transmission; in addition, since a shift mechanism (for example, including a shift motor and a sliding sleeve) is used instead of a traditional clutch and brake to achieve speed shifting, the space occupied by the transmission in the axial direction is reduced, and at the same time, the maintenance of the transmission is more convenient, thereby reducing the manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The features and advantages of the present invention will be clearly understood through the detailed description provided below with reference to the accompanying drawings. It should be understood that the following drawings are merely schematic and not necessarily drawn to scale, and therefore should not be considered as limiting the present invention, wherein:

[0020] FIG1 is a transmission principle diagram of a speed change system according to a first solution known in the prior art;

[0021] FIG2 is a transmission principle diagram of a speed change system according to a second solution known in the prior art;

[0022] FIG3 is a cross-sectional schematic diagram of a speed change system according to an embodiment of the present invention; and

[0023] FIG4 is a transmission principle diagram of a speed change system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] Embodiments of the present invention are described below with reference to the accompanying drawings. In the following description, many specific details are set forth to enable those skilled in the art to more fully understand and implement the present invention. However, it will be apparent to those skilled in the art that the present invention may be implemented without some of these specific details. Furthermore, it should be understood that the present invention is not limited to the specific embodiments described. Rather, it is contemplated that the present invention may be implemented with any combination of the features and elements described below, regardless of whether they relate to different embodiments. Therefore, the following aspects, features, embodiments, and advantages are provided for illustrative purposes only and should not be considered as elements or limitations of the claims unless expressly set forth in the claims.

[0025] In the following description, terms such as "first," "second," and the like are used to describe elements of the present application. These terms are used only to distinguish between the elements and are not used to limit the nature, order, or number of the elements. The terms "including" and "having" are used to express an open-ended inclusive meaning and indicate that additional elements / components may be present in addition to the listed elements / components.

[0026] As mentioned in the background, conventional two-speed planetary transmissions and two-speed transmissions using multi-stage gears are known in the prior art. Referring to FIG1 , a transmission principle diagram of a two-speed planetary transmission known in the prior art is shown. As can be seen, the transmission 100 shown in FIG1 includes a power input shaft (e.g., a motor output shaft 102 of a motor 101), a planetary gear mechanism, and an output shaft 111. The motor output shaft 102 is fixedly connected to the sun gear 103 of the planetary gear mechanism so as to rotate therewith. The planetary gears 104 mesh with the sun gear 103. The planetary carrier 105 is fixedly connected to the gear 109. The gear 109 meshes with the output gear 110. The output gear 110 is fixedly connected to the output shaft 111. The inner hub of the clutch 107 is located on the motor output shaft 102, and the outer hub of the clutch 107 is connected to the planetary carrier 105. One end of the brake 108 is connected to the transmission housing 112, and the other end of the brake 108 is connected to the ring gear 106 for braking the ring gear 106. When the inner and outer hubs of clutch 107 are disengaged and brake 108 is closed, the power of motor 101 is transmitted to sun gear 103, which drives planetary gears 104 to rotate. However, since ring gear 106 is fixed by brake 108, planetary carrier 105 is driven by planetary gears 104 to rotate and transmits power to gear 109. At this time, the transmission is in first gear. When the inner and outer hubs of clutch 107 are engaged and brake 108 is released, clutch 107 connects sun gear 103 and planetary carrier 105 of the planetary gear mechanism into a whole. The planetary gear mechanism rotates as a whole and drives gear 109. The speed of gear 109 is consistent with the speed of motor output shaft 102. At this time, the transmission is in second gear. However, when the transmission shifts from second gear to first gear, the high-speed motor drives the planetary gear train at a high speed, resulting in a high relative linear velocity between one end of the brake connected to the case and the other end of the brake connected to the ring gear. When the transmission shifts from first gear to second gear, the motor drives the sun gear at a high speed, resulting in an even higher relative linear velocity between the inner hub of the clutch connected to the motor output shaft and the outer hub of the clutch connected to the planetary carrier. Therefore, it can be seen that in such transmissions known in the prior art, when shifting using clutches and brakes, the high relative linear velocity between the engaging components of the brake or clutch causes rapid wear of the friction plates, resulting in a short transmission lifespan and frequent, high maintenance costs. Furthermore, such transmissions are bulky and have low vehicle space utilization.

[0027] FIG2 shows a transmission principle diagram of another conventional two-speed transmission known in the prior art. As can be seen, in transmission 200 shown in FIG2 , the motor output shaft of high-speed motor 201 is connected to gear 202 and input shaft 203. Gear 202 meshes with intermediate shaft gear 204, which is connected to intermediate shaft 205, and intermediate shaft gear 206 is connected to intermediate shaft 205. Intermediate shaft gear 204 meshes with output shaft gear 207, which meshes with output shaft gear 208. Output shaft gears 207 and 208 are mounted on output shaft 210. In this embodiment, the clutch and brake are omitted, and a shifting sleeve 209 is used instead. When sleeve 209 connects output shaft gear 208 and output shaft 210 so that they rotate together, the transmission is in first gear. When sleeve 209 connects output shaft gear 207 and output shaft 210 so that they rotate together, the transmission is in second gear. However, since the above-mentioned gearbox is not provided with a planetary gear train, in order to obtain a large transmission ratio, multi-stage gears have to be used, resulting in low utilization of the internal space of the gearbox and occupying a large space of the entire vehicle.

[0028] To this end, the present invention proposes an improved speed change system, which can achieve a more compact structural layout, more convenient maintenance, and lower manufacturing costs.

[0029] The transmission system according to the present invention includes a housing and a transmission mechanism housed in the housing, and the transmission mechanism can be used to achieve a shift between two gears. The transmission mechanism includes a power input shaft (which can be, for example, a motor output shaft), a planetary gear mechanism, and an output shaft. A first output gear and a second output gear are mounted on the output shaft, and the transmission mechanism includes a shift mechanism, which is configured to selectively engage with the first output gear or the second output gear. When the shift mechanism engages with the first output gear, power is transmitted from the power input shaft to the output shaft via the planetary gear mechanism through the first output gear and the shift mechanism, and the transmission system is in first gear. When the shift mechanism engages with the second output gear, power is transmitted from the power input shaft to the output shaft through the second output gear and the shift mechanism, without passing through the planetary gear mechanism, and the transmission system is in second gear.

[0030] It can be seen that, unlike the planetary transmissions and multi-stage gear transmissions known in the prior art, the transmission system according to the present invention avoids the problem of shortened service life due to large wear of the friction plates by omitting the clutch and the transmission. On the other hand, through the reasonable design and layout of the transmission components, two parallel transmission paths are designed (one transmission path does not pass through the planetary gear mechanism, and the other transmission path passes through the planetary gear mechanism) while retaining the planetary gear mechanism to ensure a large transmission ratio. This not only greatly reduces the number of transmission components, but also reduces the space of the entire transmission in the axial direction and the height direction, making the structure of the entire transmission system more compact.

[0031] Specifically, refer to Figure 3, which shows a schematic cross-sectional structure diagram of a speed change system 1 according to an embodiment of the present invention. The power input shaft 3 and the output shaft 11 in the speed change mechanism are rotatably mounted on the transmission housing 14 via a pair of bearings, and the power input shaft 3 and the output shaft 11 are arranged in parallel with each other and spaced apart. As shown in Figure 3, the power input shaft 3 is fixedly mounted with the sun gear 5 of the planetary gear mechanism so that the sun gear 5 can rotate along with the power input shaft 3. Preferably, the sun gear 5 can be formed as an integral part with the power input shaft 3. The sun gear 5 is engaged with the planetary gear 6 mounted on the planetary carrier 7, wherein the planetary gear 6 is rotatably mounted on the planetary carrier 7 via a rotating pin on the planetary carrier 7. The planetary carrier 7 of the planetary gear mechanism is mounted on the power input shaft 3 and can rotate relative to the power input shaft 3. The planetary gear mechanism also includes a ring gear 8 engaged with the multiple planetary gears 6, wherein the ring gear 8 is fixed to the housing 14.

[0032] The speed change mechanism further includes an input gear 4 non-rotatably connected to the power input shaft 3 and an intermediate gear 9 non-rotatably connected to the planetary carrier 7, wherein the intermediate gear 9 is arranged on a first side of the sun gear 5, and the input gear 4 is arranged on a second side of the sun gear 5 opposite the first side (see Figures 3-4). Thus, when power from the motor 2 is input via the power input shaft 3, the power input shaft 3 drives the input gear 4 and the sun gear 5 to rotate together, and the rotation of the sun gear 5 drives the planetary gears 6 to rotate. Because the ring gear 8 is fixed to the housing 14, the planetary carrier 7 is ultimately driven to rotate by the planetary gears 6, and the power is then transmitted to the intermediate gear 9 non-rotatably connected to the planetary carrier 7. As can be seen, particularly with reference to FIG4 , by arranging the power input shaft 3 and the output shaft 11 in parallel, spaced-apart configuration, and mounting two opposing output gears 10 and 12 on the output shaft 11—namely, the first output gear 10 meshing with the intermediate gear 9 and the second output gear 12 meshing with the input gear 4—power from the motor can be transmitted downward along two parallel paths via the intermediate gear 9 and the input gear 4 to the first output gear 10 and the second output gear 12 on the output shaft 11, respectively. This not only reduces the axial height of the entire gearbox, but also significantly reduces height space requirements by directly transmitting power from the input gear and intermediate gear to the output gear mounted on the output shaft, without involving a multi-stage gear transmission. It should be understood that these two different transmission paths represent two different gear positions.

[0033] To achieve gear shifting, the present invention utilizes a shift mechanism in the form of a shift sleeve 13. As a specific structural example, referring particularly to Figure 3 , the outer circumference of each of the center hubs of the first output gear 10 and the second output gear 12 is provided with external splines, while the inner circumference of the shift sleeve 13 is provided with internal splines that engage with the external splines. Shifting between first and second gears is achieved by selectively engaging the internal splines on the shift sleeve with the external splines on the first or second output gear. Of course, it should be understood that other types of shift mechanisms known in the art are also feasible, as long as they can achieve the gear shifting function intended herein. Industrial Applicability

[0034] The speed transmission system provided by the present invention can be installed in construction machinery, particularly wheeled construction machinery such as excavators and loaders. The output shaft of the speed transmission mechanism included in the speed transmission system is connected to, for example, the drive axle of the wheeled construction machinery, which is then connected to the wheels via axles. Therefore, the speed transmission mechanism can output different speeds and torques to the wheels in response to different operating conditions.

[0035] To achieve automatic shifting of the transmission system, the shift mechanism preferably includes a shift sleeve and a shift fork, wherein the shift fork can be actuated by, for example, a shift motor to move the shift sleeve. The specific working process of the transmission system according to the present invention is as follows: when it is desired to shift to first gear, a shift signal for shifting to first gear is sent to the shift motor. When the shift motor receives the shift signal, the shift fork is driven in response to the shift signal to move the shift sleeve 13 to engage with the first output gear 10 (i.e., move to the right in Figures 3 and 4 ), thereby receiving power from the intermediate gear 9. At this time, the transmission system achieves the shifting of first gear. When it is desired to shift to second gear, a shift signal for shifting to second gear is sent to the shift motor. When the shift motor receives the shift signal, the shift fork is driven in response to the shift signal to move the shift sleeve 13 to engage with the second output gear 12 (i.e., move to the left in Figures 3 and 4 ), thereby receiving power from the input gear 4. At this time, the transmission system achieves the shifting of second gear.

[0036] In addition, referring to FIG3-4 , a parking brake 15 may be installed at one end of the output shaft of the speed change mechanism to provide parking braking for the wheeled engineering machinery.

[0037] The use of the transmission system according to the present invention not only avoids the problem of shortened service life due to large wear of the friction plates of the clutch and brake, but also simplifies the transmission structure design of the entire transmission mechanism, reduces the space of the entire gearbox in the axial direction and the height direction, and makes the structure of the entire transmission system more compact.

[0038] It will be apparent to those skilled in the art that various modifications and variations may be made to the embodiments disclosed above without departing from the scope or spirit of the present invention. Other embodiments of the present invention will be apparent to those skilled in the art from the practice of the invention disclosed in this specification. This specification and the examples disclosed herein should be considered as illustrative only, and the true scope of the present invention is specified by the appended claims and their equivalents.

Claims

1. A transmission system, comprising a housing and a transmission mechanism contained in the housing, wherein the transmission mechanism comprises a power input shaft, a planetary gear mechanism and an output shaft, wherein: A first output gear and a second output gear are mounted on the output shaft, and the speed change mechanism further comprises a shift mechanism, which is configured to be selectively engageable with the first output gear or the second output gear; Among them, when the shift mechanism is engaged with the first output gear, power is transmitted from the power input shaft to the output shaft through the planetary gear mechanism through the first output gear engaged with each other and the shift mechanism, and the speed change mechanism is in the first gear. When the shift mechanism is engaged with the second output gear, power is transmitted from the power input shaft to the output shaft through the second output gear engaged with each other and the shift mechanism without passing through the planetary gear mechanism, and the speed change mechanism is in the second gear.

2. The speed change system according to claim 1, characterized in that: The power input shaft and the output shaft are arranged in parallel and spaced apart from each other.

3. The speed change system according to claim 2, characterized in that: The planetary gear mechanism includes a sun gear fixedly connected to the power input shaft, a planet carrier, a plurality of planetary gears mounted on the planet carrier and meshing with the sun gear, and a ring gear meshing with the plurality of planetary gears, wherein the ring gear is fixed to the housing.

4. The speed change system according to claim 3, characterized in that: The speed change mechanism further includes an input gear non-rotatably connected to the power input shaft, the input gear meshing with the second output gear; the speed change mechanism further includes an intermediate gear non-rotatably connected to the planet carrier, the intermediate gear meshing with the first output gear.

5. The speed change system according to claim 4, characterized in that: The intermediate gear is arranged on a first side of the sun gear, and the input gear is arranged on a second side of the sun gear opposite to the first side.

6. The transmission system according to any one of claims 3 to 5, characterized in that: The sun gear and the power input shaft are formed as an integral piece.

7. The speed change system according to any one of claims 1 to 5, characterized in that: The shift mechanism includes a shift sleeve and a shift fork, wherein the shift fork is actuable to move the shift sleeve to engage with the first output gear or the second output gear.

8. The speed change system according to claim 7, characterized in that: External splines are arranged on the outer circumferences of the central hubs of the first output gear and the second output gear, and internal splines that can engage with the external splines are arranged on the inner circumference of the shift sleeve.

9. An engineering machine, characterized in that: The construction machine comprises a transmission system according to any one of claims 1 to 8.

10. The construction machine according to claim 9, characterized in that: The output shaft of the speed change mechanism is connected to the drive axle of the engineering machinery, and the drive axle is connected to the wheels through half shafts.

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