Transmission system, and construction machinery 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, a clutch, a brake and an output shaft; the planetary gear mechanism comprises a sun gear fixedly connected to the power input shaft, a planet carrier, a plurality of planet gears which are mounted on the planet carrier and mesh with the sun gear, and a ring gear which meshes with the plurality of planet gears; and an inner hub of the clutch is connected to the planet carrier, and an outer hub of the clutch is connected to the ring gear. By using the transmission system of the present invention, the relative linear speed between engagement components of the clutch and the brake can be reduced, thereby reducing heat generation and wear of friction plates thereof, and the maintenance cost and frequency of a gearbox can be reduced.

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 for engineering machinery, and specifically to a speed change system and engineering machinery comprising the speed change system. Background Art

[0002] Engineering machinery, particularly wheeled engineering machinery, often requires a transmission system to adapt to varying operating conditions, achieving variable speed and torque outputs for each operating condition. 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 various planetary transmissions suffer from 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 results in a short transmission lifespan, frequent maintenance, and high maintenance costs.

[0003] Therefore, it is necessary to provide an improved transmission system so as to improve the wear problem of the friction plates of the clutch and / or brake.

[0004] Summary of the Invention

[0005] 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.

[0006] 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 includes a power input shaft, a planetary gear mechanism, a clutch, a brake and an output shaft, 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, the inner hub of the clutch is connected to the planetary carrier, and the outer hub of the clutch is connected to the ring gear.

[0007] According to an embodiment of the present invention, the first engaging portion of the brake is connected to the end cover of the housing, and the second engaging portion of the brake is connected to the ring gear, so that the first and second engaging portions of the brake are located radially inside the ring gear.

[0008] According to one embodiment of the present invention, when the inner hub and the outer hub of the clutch are in a disengaged state and the first and second engaging parts of the brake are in an engaged state, the ring gear is fixed by the brake, so that power is transmitted from the power input shaft to the output shaft through the sun gear and the planetary carrier in sequence. At this time, the speed change system is in first gear.

[0009] According to one embodiment of the present invention, when the inner hub and the outer hub of the clutch are in an engaged state and the first and second engaging parts of the brake are in a disengaged state, the planetary carrier and the ring gear are connected into a whole through the clutch, so that power is transmitted from the power input shaft to the output shaft through the planetary gear mechanism that rotates as a whole. At this time, the speed change system is in second gear.

[0010] According to an embodiment of the present invention, the planet carrier is connected to an intermediate gear via an intermediate shaft, the intermediate gear is engaged with an output gear, and the output gear is fixedly connected to the output shaft.

[0011] According to one embodiment of the present invention, the sun gear and the power input shaft are formed as an integral piece.

[0012] According to one embodiment of the present invention, the clutch is a hydraulic friction plate clutch.

[0013] According to one embodiment of the present invention, the brake is a hydraulic friction plate brake.

[0014] According to another aspect of the present invention, there is further provided an engineering machine, which includes the speed change system as described above.

[0015] 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.

[0016] The transmission system according to the present invention can reduce the relative linear speed between the engaging parts of the clutch and the brake, thereby reducing the heat generation and wear of the friction plate, and reducing the cost and frequency of transmission maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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:

[0018] FIG1 is a transmission principle diagram of a speed change system known in the prior art;

[0019] FIG2 is a transmission principle diagram of a speed change system according to an embodiment of the present invention; and

[0020] FIG3 is a schematic cross-sectional view of a speed change system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0021] 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.

[0022] As used hereinafter, the terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements / components other than the listed elements / components.

[0023] As mentioned in the background, conventional two-speed planetary transmissions are known in the art. Referring to FIG1 , a transmission principle diagram of a two-speed planetary transmission known in the 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. The first engaging portion of the brake 108 is connected to the inner periphery of the transmission housing, and the second engaging portion of the brake 108 is connected to the ring gear 106 for braking the ring gear 106. When the inner hub and outer hub of clutch 107 are disengaged and the first and second engaging portions of brake 108 are engaged, 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 gearbox is in first gear. When the inner hub and outer hub of clutch 107 are engaged and the first and second engaging portions of brake 108 are disengaged, 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. At this time, the gearbox is in second gear, and the speed of gear 109 is consistent with the speed of motor output shaft 102. 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 the first engaging portion of the brake connected to the outer periphery of the transmission case and the second engaging portion of the brake connected to the ring gear. Furthermore, 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 this type of transmission known in the prior art, when shifting gears 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 service life of the transmission and frequent and costly maintenance.

[0024] To this end, the present invention proposes an improved speed change system, which enables more convenient maintenance and lower manufacturing costs.

[0025] To improve friction plate wear in clutches (such as hydraulic friction plate clutches) and brakes (such as hydraulic friction plate brakes), it's crucial to reduce the relative linear velocity between the clutch and brake's engaging parts (e.g., friction plates) at the shifting moment. It's important to note that linear velocity V depends on two parameters: angular velocity ω and rotational radius r. Therefore, reducing both angular velocity and rotational radius can mitigate friction plate wear.

[0026] Referring to Figure 2, the speed change system 1 according to the present invention includes a case 14 and a speed change mechanism accommodated in the case 14, the speed change mechanism includes a power input shaft 3 connected to the motor 2, a planetary gear mechanism, a clutch 8, a brake 9 and an output shaft 13, the planetary gear mechanism includes a sun gear 4 fixedly connected to the power input shaft 3, a planetary carrier 6, a plurality of planetary gears 5 mounted on the planetary carrier 6 and meshing with the sun gear 4, and a ring gear 7 meshing with the plurality of planetary gears 5.

[0027] Specifically, refer to Figure 3, which shows a schematic cross-sectional structure of a speed change system 1 according to an embodiment of the present invention. The power input shaft 3 is fixedly mounted with a sun gear 4 of a planetary gear mechanism, so that the sun gear 4 can rotate along with the power input shaft 3. Preferably, the sun gear 4 can be formed as an integral part with the power input shaft 3. The sun gear 4 is engaged with the planetary gear 5 mounted on the planetary carrier 6, wherein the planetary gear 5 is rotatably mounted on the planetary carrier 6 via a rotating pin on the planetary carrier 6. The planetary carrier 6 and the intermediate gear 11 are respectively non-rotatably connected to the intermediate shaft 10, so that the planetary carrier 6, the intermediate gear 11 and the intermediate shaft 10 can rotate together. The intermediate gear 11 is engaged with the output gear 12, and the output gear 12 is non-rotatably connected to the output shaft 13.

[0028] However, unlike the planetary gearbox known in the prior art as shown in Figure 1, in the transmission system according to the present invention, the inner hub of the clutch 8 is connected to the planetary carrier 6, and the outer hub of the clutch 8 is connected to the ring gear 7; and the first engaging part of the brake 9 is connected to the end cover of the case (the end cover is connected to the case at one end of the case 14) via a spline joint, for example, and the second engaging part of the brake 9 is connected to the ring gear 7 via an intermediate sleeve, for example, so that the first engaging part and the second engaging part of the brake 9 are on the radial inside of the ring gear 7, thereby providing braking to the ring gear 7.

[0029] Thus, when the inner and outer hubs of clutch 8 are disengaged and the first and second engagement portions of brake 9 are engaged, the power of motor 2 is transmitted to sun gear 4 via power input shaft 3, which drives planetary gears 5 to rotate. However, since ring gear 7 is fixed by brake 9, planetary carrier 6 is driven to rotate by planetary gears 5, thereby transmitting power to intermediate gear 11 via intermediate shaft 10 and ultimately to output shaft 13 via output gear 12. At this point, the transmission is in first gear. In this first gear transmission path, the relative linear velocity of the friction plates of clutch 8 corresponds to the relative linear velocity between ring gear 7 and planetary carrier 6. Since the rotational speed of planetary carrier 6 is much lower than that of power input shaft 3 (i.e., the angular velocity ω of the friction plates is reduced), the relative linear velocity of the friction plates of the clutch according to the present invention can be reduced by, for example, 30% compared to the embodiment shown in FIG.

[0030] When the inner hub and outer hub of the clutch 8 are engaged and the first engaging part and the second engaging part of the brake 9 are disengaged, the clutch 8 connects the ring gear 7 and the planetary carrier 6 of the planetary gear mechanism as a whole, so that the entire planetary gear mechanism rotates as a whole, and then transmits power to the intermediate gear 11 through the intermediate shaft 10 and finally to the output shaft 13 via the output gear 12. At this time, the speed of the intermediate gear 11 is consistent with the speed of the power input shaft 3, and the gearbox is in second gear. In the transmission route of this second gear, the relative linear velocity of the friction plate of the brake 9 corresponds to the relative linear velocity between the ring gear 7 and the end cover 15. Since the first engaging part of the brake is connected to the end cover (rather than directly connected to the inner periphery of the housing as in the scheme shown in FIG1 ), the first engaging part and the second engaging part of the brake are on the radial inner side of the ring gear 7. Therefore, compared with the scheme shown in FIG1 (wherein the engaging part of the brake, such as the friction plate, is on the radial outer side of the ring gear), the diameter of the friction plate of the brake is effectively reduced (i.e., the rotation radius r of the friction plate is reduced). Therefore, according to the technical solution of the present invention, the relative linear velocity of the friction plate of the clutch can be reduced by, for example, 29% compared with the scheme shown in FIG1 .

[0031] In this way, since the linear speed of the friction plates of the clutch and brake is effectively reduced, the heat generated and the wear of the friction plates during friction are effectively reduced, thereby greatly improving the service life of the friction plates of the clutch and brake and reducing the maintenance cost and frequency of the gearbox. Industrial Applicability

[0032] 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, a drive axle of the wheeled construction machinery, which is then connected to the wheels via axles. Thus, the speed transmission mechanism can output different speeds and torques to the wheels.

[0033] The specific working process of the speed change system according to the present invention is as follows: when it is desired to switch to the first gear, the clutch controller sends a disengagement signal to the clutch and the brake controller sends an engagement signal to the brake, so that the inner hub and the outer hub of the clutch are disengaged, and the first and second engaging parts of the brake are engaged, so that the power from the motor is transmitted from the power input shaft to the output shaft through the sun gear, the planetary carrier, the intermediate gear, and the output gear in sequence, and the speed change system realizes the switching of the first gear; when it is desired to switch to the second gear, the clutch controller sends an engagement signal to the clutch and the brake controller sends a disengagement signal to the brake, the clutch engages its inner hub and the outer hub in response to the received signal, and the brake disengages its first and second engaging parts in response to the received signal, so that the power from the motor is transmitted from the power input shaft to the output shaft through the planetary gear mechanism that rotates as a whole, and the speed change system realizes the switching of the second gear.

[0034] In addition, referring to FIG. 2-3 , a parking brake 16 may be installed at one end of the intermediate shaft of the transmission mechanism to provide parking brakes for, for example, wheeled engineering machinery.

[0035] By adopting the transmission system according to the present invention, by connecting the inner hub of the clutch to the planetary carrier and the outer hub of the clutch to the ring gear, and connecting the first engaging part of the brake to the case end cover and the second engaging part of the brake to the ring gear so that the first engaging part and the second engaging part of the brake are located radially inward of the ring gear, the relative linear speed of the friction plates of the clutch and the brake can be reduced, thereby slowing down the wear of the friction plates, increasing the service life of the clutch and the brake, and reducing the maintenance cost of the transmission.

[0036] 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, a clutch, a brake and an output shaft, wherein the planetary gear mechanism comprises 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 inner hub of the clutch is connected to the planet carrier, and the outer hub of the clutch is connected to the ring gear.

2. The speed change system according to claim 1, characterized in that: The first engaging portion of the brake is connected to the end cover of the case, and the second engaging portion of the brake is connected to the ring gear so that the first engaging portion and the second engaging portion of the brake are located radially inside the ring gear.

3. The speed change system according to claim 2, characterized in that: When the inner hub and the outer hub of the clutch are in a disengaged state and the first engaging part and the second engaging part of the brake are in an engaged state, the ring gear is fixed by the brake, so that power is transmitted from the power input shaft to the output shaft through the sun gear and the planetary carrier in sequence. At this time, the transmission system is in first gear.

4. The speed change system according to claim 2, characterized in that: When the inner hub and outer hub of the clutch are in an engaged state and the first engaging part and the second engaging part of the brake are in a disengaged state, the planetary carrier and the ring gear are connected as a whole through the clutch, so that power is transmitted from the power input shaft to the output shaft through the planetary gear mechanism that rotates as a whole. At this time, the transmission system is in second gear.

5. The speed change system according to claim 3 or 4, characterized in that: The planet carrier is connected to an intermediate gear via an intermediate shaft. The intermediate gear is meshed with an output gear. The output gear is fixedly connected to the output shaft.

6. The speed change system according to any one of claims 1 to 4, characterized in that: The sun gear and the power input shaft are formed as an integral piece.

7. The transmission system according to any one of claims 1 to 4, characterized in that: The clutch is a hydraulic friction plate clutch.

8. The transmission system according to any one of claims 1 to 4, characterized in that: The brake is a hydraulic friction plate brake.

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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