additional transmission

Abstract

An auxiliary transmission (1) comprising a housing (2) provided with openings for accommodating bearings, wherein a shaft provided with at least one gear is mounted between a pair of oppositely arranged bearings, wherein the shaft provided for transmitting the input torque is a drive shaft (4) and the shaft provided for transmitting the output torque is an output shaft (5), characterized in that the drive shaft (4) is mounted in the housing (2) by means of a pair of rolling bearings (7) and is provided with splines, which splines are provided for attaching a driving gear (6), that the output shaft (5) is mounted in the housing (2) by means of a pair of rolling bearings (7) and is provided with splines, which splines are provided for attaching a driven gear (8), and that a countershaft journal (9) is arranged between the drive shaft (4) and the output shaft (5),which is mounted in the housing (2) in a rotationally fixed manner, wherein a gear (10) rotatably mounted in rolling bearings (7) is arranged on the countershaft journal (9).

Description

Technical area

[0001] The present technical solution concerns the construction and arrangement of an auxiliary transmission intended primarily for vehicles with a central support tube, and thus concerns the automotive field, in particular vehicle construction with regard to heavy trucks and their drive trains. State of the art

[0002] Auxiliary gearboxes are a standard component of drivetrains and are used to adjust the distribution of torque supplied from a main gearbox in various directions, for example, to multiple driven axles or other driven units. An auxiliary gearbox adjusts the speed and torque of an upstream main gearbox.

[0003] From technical practice, an auxiliary gearbox intended for vehicles with a central support tube is known, which was developed for use in vehicles of the manufacturer Tatra. This auxiliary gearbox has the same, standardized dimensions across its entire width, making it suitable for installation in the chassis of vehicles with a central support tube. The auxiliary gearbox consists of three main shafts: a drive shaft, a countershaft, and an output shaft. Each of these shafts has a gear. A drive gear is grooved on the drive shaft. The countershaft carries two gears, namely the intermediate gear A and the intermediate gear B. A driven gear is grooved on the output shaft.The drive shaft is supported within the auxiliary transmission housing by two identical tapered bearings, and the countershaft is also supported within the auxiliary transmission housing by two identical tapered bearings. In contrast, the driven shaft is supported within the auxiliary transmission housing by two different tapered bearings. The drive shaft also features a flange at the front for connecting a universal joint, and an oil pump at the rear, downstream of the corresponding bearing, which supplies the entire auxiliary transmission with lubricating oil.

[0004] The document CN102673394 "Mining anti-explosion trackless rubber tire vehicle chassis" describes the design of an explosion-proof chassis intended for off-road vehicles. However, the latter document does not specify any specific characteristics of the auxiliary drive, such as the number of gears, number of shafts, housing design, or shaft bearings. One of the disadvantages of the technical solution described in the latter document is that the design of the auxiliary drive in question does not allow for the integration of a differential gear / torque distributor.

[0005] The transmissions used in vehicles equipped with a central support tube are disclosed in the document US2020269686 "Modular drive train and a vehicle comprising such a drive train." The latter patent document deals with the installation of the drive train in a modular vehicle, but only mentions a transmission, thus no additional transmission. Apart from a mention of the integration of a differential gear into the housing of the main transmission, no essential information such as the number of gears, number of shafts, housing design, or shaft bearings can be found here. The drawings included in the technical documentation show that, according to the present technical solution, the number of gears in the additional transmission is lower, namely three.

[0006] The document CZ131859 ​​"Arrangement of a transmission system for a vehicle with four driven axles and independent wheel suspension" merely discloses the arrangement of a transmission system for a vehicle with four driven axles. According to this patent, a chassis is divided into two assemblies: a front drive unit and a rear drive unit.

[0007] The most important objective of this technical solution is to reduce weight and the number of required gear stages of the auxiliary transmission, as well as the number of required components. However, the innovative design should allow for the integration of a differential or torque distributor, as well as a brake or a flange for driving other connected technologies. Such an auxiliary transmission should also be adaptable with regard to the freely adjustable gear ratios achievable by changing the shaft center distance and the size of the gears. The intended auxiliary transmission should be suitable for a wide variety of vehicle drivetrain configurations, including those with 4x4, 6x6, 8x8 axle configurations and selectable front-wheel drive, as well as those with 4x4, 6x6, 8x8 axle configurations and permanent front-wheel drive.The intended additional transmission should allow for faster and easier assembly and be more cost-effective to manufacture. Essence of the technical solution

[0008] An auxiliary gearbox is a component of a vehicle's drivetrain. The input torque of the auxiliary gearbox is generated by a drive unit, namely an engine. The drive unit can be an internal combustion engine, an electric motor, or a combination of the two. The drive torque can either be fed from the engine into the main gearbox and then via a propeller shaft to the auxiliary gearbox, or it can be provided that the torque is transmitted directly to the auxiliary gearbox via a propeller shaft. This arrangement is common, for example, when the drive unit is based on an electric motor. The auxiliary gearbox housing is then arranged within the structure of the central support tube, namely between the front and rear sections of the same.

[0009] The auxiliary gear consists of a housing with openings for accommodating bearings. The shafts are then rotatably mounted in opposing roller bearings. The shaft carries a gear, either rotatably or non-rotatably mounted, with the meshing teeth of the individual gears meshing with each other to transmit the respective drive torque. This enables the speed and magnitude of the drive torque to be adjusted. The input torque is transmitted to the auxiliary gear via a drive shaft. The latter shaft is mounted in the housing by means of a pair of roller bearings. The drive shaft is provided with splines, by means of which the driving gear is mounted.The output torque is transmitted from the driving gear to the intermediate gear, with the teeth of the driving gear and the intermediate gear being in direct mutual mesh. The intermediate gear is either rotatably supported by rolling bearings housed on a layshaft journal, which is non-rotatably mounted in the housing, or is non-rotatably splined to a layshaft, which is rotatably mounted in the housing via a pair of rolling bearings. The output torque of the auxiliary gear is transmitted by a driven shaft, which in turn is rotatably mounted in the housing by means of a pair of rolling bearings. The driven shaft is provided with splines, by means of which a driven gear is non-rotatably splined. The teeth of the driven gear are in direct mesh with the teeth of the intermediate gear.

[0010] In an advantageous embodiment, the drive shaft is provided with a flange on one side, which serves as a connecting element between this drive shaft and a propeller shaft. On the other side, the drive shaft carries an oil pump, which ensures the lubrication of the auxiliary transmission with a lubricant, namely gear oil. The oil pump is located on the outer side of the housing, at one end of the drive shaft, where it is connected downstream of a rolling bearing housed in the corresponding wall of the housing.

[0011] In another advantageous embodiment, the auxiliary transmission includes a brake, which is also arranged on the drive shaft. The brake is arranged on the drive shaft from the outer side of the housing, downstream of the oil pump.

[0012] In a further advantageous embodiment, the auxiliary transmission further comprises a first clutch with a flange for driving other connected technology, for example a pump or a cable winch. The clutch provided with the aforementioned flange is arranged on the drive shaft in such a way that it replaces the brake from the previous advantageous embodiment. The oil pump is always followed first by the first clutch and only then by the flange. In this advantageous embodiment, the auxiliary transmission further comprises an idle mechanism. The idle mechanism is formed by a second clutch arranged on the driven shaft. In this advantageous embodiment, the driven gear is rotatably arranged on the driven shaft.

[0013] In a further advantageous embodiment, the driven gear is rotatably mounted on the driven shaft. In this advantageous embodiment, the auxiliary transmission also includes a lockable differential or a torque distributor, which are arranged within an inner housing rotatably mounted in the auxiliary transmission housing. The inner housing is non-rotatably connected to the driven gear. The output of the differential or torque distributor is provided with two output shafts.

[0014] In a further advantageous embodiment, the additional transmission simultaneously comprises a brake arranged on the drive shaft and a lockable differential gear or a torque distributor, the latter replacing the driven shaft.

[0015] The most important advantage of the innovative auxiliary gearbox is that its design enables a weight reduction of the entire drivetrain of almost 100 kg, a value corresponding to almost 25% of the total weight of the original drivetrain. This lower weight is accompanied by significant material savings. The tapered upper and middle sections of the auxiliary gearbox necessitate a desirable lengthening of the corresponding universal joint. This reduces the cardan error and suppresses the vibrations associated with this error. The wider lower section also allows for the integration of a differential gear or a torque distributor. The innovative auxiliary gearbox can be equipped with a brake in the upper section or with a flange for driving other connected technologies.A further advantage of this technical solution is that one gear has been eliminated, meaning that the novel design requires only three gears instead of the original four to operate the auxiliary transmission. Just like the original auxiliary transmission, this novel auxiliary transmission is installed in the vehicle's supporting structure, housed in the lower part of the structure and connected to the front and rear sections of the supporting tube. In this respect, the auxiliary transmission housing is sufficiently designed to withstand both bending and torsional stresses. At the same time, the novel auxiliary transmission is highly versatile in terms of the achievable gear ratios, making it possible to set any desired gear ratio in the range from i = 0.5 to i = 2.5 by changing the shaft center distance and the size of the gears.Depending on its design, the auxiliary transmission can be used for a wide variety of vehicle drivetrain configurations, including those with 4x4, 6x6, 8x8 axle configurations and selectable front-wheel drive, as well as those with 4x4, 6x6, 8x8 axle configurations and permanent front-wheel drive. The above-mentioned advantages, taken together, also mean that the innovative auxiliary transmission allows for faster and easier assembly, is more cost-effective to manufacture, and generates less vibration. Explanation of the drawings

[0016] The present technical solution is explained in more detail below with the help of the attached drawings, which show: Fig. in a simplified view, the drive train of a vehicle, formed by a drive unit with a flange arranged in the output area of ​​a main gearbox and connected via a cardan shaft to the flange of a drive shaft of an additional gearbox, which is arranged between the front and rear parts of a central support tube, Fig. in a simplified view, the drive train of a vehicle, formed by a flanged electric motor, which is connected via a cardan shaft to the flange of a drive shaft of an additional transmission, wherein the additional transmission is arranged between the front and the rear part of the central support tube, Fig. an auxiliary gear in the original design with four gears, including a driving gear, two intermediate gears and a driven gear, the driving gear being in engagement with an intermediate gear which is different from the one with which the driving gear is in engagement, the arrangement of the auxiliary gear being shown within the central support tube assembly, the drive shaft being provided with a flange and carrying an oil pump, Fig. a novel auxiliary gear with three gears, one of which is a driving gear, one of which is an intermediate gear and one of which is a driven gear, the driving gear being in engagement with the intermediate gear, which is also in engagement with the driven gear, the arrangement of the auxiliary gear within the assembly of the central support tube being evident in the figure, the drive shaft being provided in a flange and carrying an oil pump, and instead of the countershaft, a countershaft journal being provided which is mounted in a rotationally fixed manner in the housing and carries an intermediate gear which is rotatably arranged on the same, Fig. the design of the additional gearbox according to Fig. , which is supplemented by a brake located behind the oil pump, Fig. the representation of an additional transmission in a novel design, wherein in this design the additional transmission is provided with a lockable differential gear or torque distributor arranged within the inner housing, by which the driven shaft is replaced and which is connected in a rotationally fixed manner to the driven gear, and wherein two output shafts are arranged on the output side of the lockable differential gear or the torque distributor, Fig. a new type of additional transmission Fig. , the additional transmission being provided with both a brake and a differential or a torque distributor, Fig. A novel auxiliary transmission, with a first clutch arranged downstream of the oil pump on the drive shaft, which is provided with a flange for driving additional connected technology. In this design, the auxiliary transmission is equipped with an idle mechanism. This is achieved by attaching a second clutch to the driven shaft, via which the driven gear is rotatably mounted on the driven shaft. Examples

[0017] The Fig. The additional transmission 1 shown forms an intermediate component of the drive train of a vehicle, which is provided with a central support tube, wherein the tube is further divided into a front part 20 and a rear part 21 in connection with the accommodation of the additional transmission 1. The drive torque is generated by a drive unit 18, which is more commonly known as an engine. From the drive unit 18, the drive torque is fed into a transmission 19 or, as is the case with an electric drive, directly into an additional transmission 1. The drive unit 18 can be an internal combustion engine, an electric motor, or a combination thereof.The transmission of drive torque between the drive unit 18, the transmission 19, and the auxiliary transmission 1 is effected by means of the cardan shafts 22, whereby the drive unit 18 and / or the transmission 19 and / or the auxiliary transmission 1 can be provided with a flange 11 in its input and / or output area for securing the cardan shaft 22. The housing 2 of the auxiliary transmission 1 is arranged within the structure of the central support tube, namely between the front part 20 and the rear part 21 thereof.

[0018] The Fig. To illustrate the difference between the original arrangement of the additional gear 1 and the new version thereof, the figure shows the original arrangement of the additional gear 1 with four gears 6, 8, 10. This additional gear 1 thus comprises a driving gear 6, two intermediate gears 10, and a driven gear 8. The driven gear 8 meshes with the intermediate gear 10, which is different from the one with which the driving gear 6 meshes. The figure shows the arrangement of the additional gear 1 within the central support tube assembly. The drive shaft 4 of the additional gear 1 is provided with a flange 11 at its input end and with an oil pump 12 provided for the additional gear 1 at its output end, the latter supplying the entire additional gear 1 with lubricating oil.All shafts 3, 4, 5 are rotatably mounted in the housing 2 of the auxiliary gear 1 such that the individual ends of shafts 3, 4, 5 are mounted in the respective roller bearings 7, which are pressed into the openings provided for this purpose in the housing 2. The gears 6, 8, 10 are non-rotatably attached to the shafts 3, 4, 5 via serrations formed in the respective interfaces between the shafts 3, 4, 5 and the gears 6, 8, 10. The design and size of the roller bearing 7 correspond to the requirements associated with the direction and magnitude of the forces to be transmitted. Example 1:

[0019] This is an example of a not-shown design of a novel auxiliary transmission 1 according to the present application. While the original design required four gears 6, 8, 10 to transmit the torque, and the housing 2 of the auxiliary transmission 1 was the same width along their entire length, in the present exemplary embodiment of the present technical solution, only three gears 6, 8, 10 are sufficient, and the housing 2 is significantly narrower in its upper part than in its lower part, where the driven shaft 5 is housed. The auxiliary transmission 1 thus comprises an output shaft 4 provided with a driving gear 6, a countershaft 3 provided with an intermediate gear 10, and an output shaft 5 provided with a driven gear 8.In the present example, the driving gear 6 is in direct mesh with the intermediate gear 10, which in turn is in direct mesh with the driven gear 8. The gears 6, 8, 10 are provided with helical gearing in the present example, which is why the rolling bearings 7 are designed as tapered roller bearings. Each of the shafts 3, 4, 5 is mounted in a pair of rolling bearings 7 of the same type, whose sizes and designs are identical. The present additional gear 1 is also arranged with its lower part between the front part 20 and the rear part 21 of the central support tube. The drive shaft 4 of the additional gear 1 is provided with a flange 11 at its input end and with an oil pump 12 intended for the additional gear 1 at its output end. Example 2:

[0020] This is a concrete example of the implementation of this technical solution, which is presented in Fig. is shown. In terms of arrangement and features, the presently presented example bears great similarity to the design of the auxiliary transmission 1 according to Example 1. The only, yet very significant, difference is that in the present exemplary embodiment, the countershaft 3 is replaced by a countershaft journal 9. The countershaft journal 9, in contrast to the countershaft 3, is mounted in the housing 2 in a rotationally fixed manner, and the intermediately mounted gear 10 is thus rotatably mounted on the countershaft journal 9 via a pair of rolling bearings 7. Example 3:

[0021] The Fig. The concrete example of the implementation of the present technical solution presented is structurally based on the previous example 2, but with the difference that the drive shaft 4, in the area of ​​its exit from the outside of the housing 2, after passing through the rolling bearing 7, is equipped not only with the oil pump 12 but also with the downstream brake 13. The task of the brake 13 is to decelerate the entire drive train. Depending on the selected design, the brake 13 can also be used as a parking or relief brake. Example 4:

[0022] The Fig. The concrete example of the implementation of the present technical solution shown is based on Example 1 in terms of design. The difference compared to Example 1 (not shown) is that in the present example, the driven shaft 5 is omitted, and instead of that shaft, the additional transmission 1 is provided with a lockable differential gear arranged in the internal housing 16. The internal housing 16 is connected in a rotationally fixed manner to the driven gear 8. Two output shafts 17 are arranged on the output side of the lockable differential gear.

[0023] According to another example of the implementation of the present technical solution, also not shown, which is based on Example 4, the lockable differential gear is replaced by a torque distributor, which is again arranged in the internal housing 16. The internal housing 16 is connected in a rotationally fixed manner to the driven gear 8. Example 5:

[0024] The Fig. The concrete example of the implementation of the present technical solution shown is based on the design of example 4, but with the difference that the drive shaft 4, in the area of ​​its exit from the outside of the housing 2, after passing through the rolling bearing 7, is provided with the downstream brake 13 in addition to the oil pump 12. Example 6:

[0025] The Fig.The concrete example of the implementation of the present technical solution shown is based on Example 5 in terms of construction, with two differences. The first clutch 14 is arranged on the drive shaft 4, which is connected downstream of the oil pump 12 and is provided with the flange 11 for driving other connected technologies. The implementation of the technical solution according to the present example also differs from Example 5 in that the additional transmission 1 is equipped with an idle mechanism. This is achieved by attaching a second clutch 15 to the driven shaft 5, via which second clutch 15 the driven gear 8 is rotatably mounted on the driven shaft 5. Industrial applicability

[0026] This technical solution is used primarily in the drivetrains of trucks manufactured by Tatra, thus in the construction of heavy trucks. List of reference symbols 1 additional gearbox 2 additional gear housings 3 Countershaft 4 drive shaft 5 Output shaft 6 driving gear 7 rolling bearings 8 driven gear 9 lay pins 10 intermediate gear 11 Flange 12 Oil pump 13 Brake 14 first clutch 15 second clutch 16 internal housing 17 Output shaft 18 Drive unit 19 gearboxes 20 front part of the central support tube 21 rear part of the central support tube 22 Cardan shaft QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] CN 102673394

[0004] US 2020269686

[0005]

Claims

[1] An auxiliary transmission (1) comprising a housing (2) provided with openings for accommodating bearings, wherein a shaft provided with at least one gear is mounted between a pair of oppositely arranged bearings, wherein the shaft provided for transmitting the input torque is a drive shaft (4) and the shaft provided for transmitting the output torque is an output shaft (5), characterized bythat the drive shaft (4) is mounted in the housing (2) by means of a pair of rolling bearings (7) and is provided with serrations, which toothing is provided for the attachment of a driving gear (6), that the output shaft (5) is mounted in the housing (2) by means of a pair of rolling bearings (7) and is provided with serrations, which toothing is provided for the attachment of a driven gear (8), and that between the drive shaft (4) and the output shaft (5) there is arranged a countershaft journal (9) which is mounted in the housing (2) in a rotationally fixed manner, wherein a gear (10) which is rotatably mounted intermediately in rolling bearings (7) is arranged on the countershaft journal (9). [2] The additional transmission (1) according to claim 1, characterized by that the countershaft pin (9) is replaced by a countershaft (3) which is rotatably arranged in the housing (2) in such a way that it is mounted in a pair of rolling bearings (7). [3] The additional transmission (1) according to claim 1 or 2, characterized by that the drive shaft (4) is provided at one end with a flange (11) and the drive shaft (4) carries at its other end an oil pump (12), which pump, viewed from the outer part of the housing (2), is arranged behind the position provided for the rolling bearing (7) supporting the drive shaft (4). [4] The additional transmission (1) according to claim 3, characterized by that it further comprises a brake (13) which is arranged on the drive shaft (4) behind the location provided for the oil pump (12). [5] The additional transmission (1) according to claim 3, characterized byin that it further comprises a first clutch (14) with a flange (11) arranged on the output shaft (4) behind the location provided for the oil pump (12), and an idle mechanism, the latter being formed by a second clutch (15) arranged on the driven shaft (5), and the driven gear (8) being rotatably arranged on the driven shaft. [6] The additional transmission (1) according to one of claims 1 to 4, characterized by that the additional transmission (1) further comprises a lockable differential transmission or a torque distributor, which are arranged within an inner housing (16) rotatably mounted in the housing (2) of the additional transmission (1) and are connected in a rotationally fixed manner to the driven gear (8), wherein the output of the differential transmission or of the torque distributor is provided with two output shafts (17). [7] The additional transmission (1) according to claims 4 and 6, characterized bythat it simultaneously comprises the brake (13) and a lockable differential gear or a torque distributor.

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