A METHOD THEREOF

CROSS REFERENCE TO RELATED APPLICATION

This Application is based on and derives the benefit of Indian Provisional Application 202211031702 filed on 2 ^nd June 2022, the contents of which are incorporated herein by reference.

TECHNICAL FIELD

[001] The embodiments herein generally relate to drivetrains in vehicles and more particularly, to the drivetrain in the vehicle for achieving reduced wheelbase.

BACKGROUND

[002] Generally, a differential unit in is provided in a drivetrain of the vehicle for rotating the outer wheels faster than inner wheels while the vehicle is taking turns. Typically, a tail pinion (differential pinion) is connected to a range output shaft of a range transmission unit and is meshed with a differential ring gear in vehicle transmissions, particularly in transmissions of agricultural vehicles such as tractors. The tail pinion and the differential ring gears are configured to turn the drive from the drive shaft at an angle of 90 degrees to drive the wheels of the vehicle. The drive shaft is connected to an input side of the tail pinon. As the tail pinion and differential ring gear mesh, the torque and rotational motion of the differential ring gear is transferred to the rear axle which ultimately drives the tractor’s wheels.

[003] Typically, the tail pinion and the differential ring gear are located in a differential casing of the differential unit. However, the arrangement and location of the tail pinion and the differential ring gear within the differential unit may vary depending on the specific design and configuration of the vehicle’s transmission. Fig. 1 depicts a conventional drivetrain (10) in vehicle such as a tractor. The drivetrain (10) includes a speed transmission unit (20), a range transmission unit (30), a tail pinion (42), (differential pinion), a differential ring gear (44), a differential output shaft (46), a differential planetary gear set (50), a pair of rear axle driving gears (58) and a rear axle (60). The tail pinion (42) is rotatably connected to a range output shaft of the range transmission unit (30) and is meshed with the differential ring gear (44). The differential ring gear (44) is rotatably connected to the differential output shaft (46) via the differential planetary gear set (50). The differential output shaft (46) is rotatably connected to the rear axle (60) via the rear axle driving gears (58). In the conventional drivetrain (10), the direction of power flow from an engine to differential ring gear (44) and the direction of power flow from the differential ring gear (44) to the rear axle (60) are in the same direction. The conventional constructional arrangement of tail pinion (42) and the differential ring gear (44) along with the differential planetary gear set (50) and the rear axle driving gears (58) increases an overall wheelbase and length of the vehicle due to placement of the rear axle (60) at the rear of and spaced away from the differential ring gear (44).

[004] Therefore, there exists a need for a drivetrain in a vehicle for achieving reduced wheelbase, which obviates the aforementioned drawbacks.

OBJECTS

[005] The principal object of embodiments herein is to provide a drivetrain in a vehicle for achieving reduced wheelbase.

[006] Yet another object of embodiments herein is to provide a compact drivetrain and a compact housing for rear transmission of the vehicle.

[007] These and other objects of embodiments herein will be better appreciated and understood when considered in conjunction with following description and accompanying drawings. It should be understood, however, that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF DRAWINGS

[008] The embodiments are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:

[009] Fig. 1 illustrates a conventional drivetrain for a vehicle; [0010] Fig. 2 illustrates a drivetrain in a vehicle for achieving reduced wheelbase, according to embodiments as disclosed herein; and

[0011] Fig. 3 depicts a flowchart indicating steps of a method of providing power flow in the drivetrain of the vehicle, according to embodiments as disclosed herein.

DETAILED DESCRIPTION

[0012] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

[0013] The embodiments herein achieve a drivetrain in a vehicle for achieving reduced wheelbase. The embodiments herein also achieve compact drivetrain with compact rear transmission housing, and optimized oil sump capacity. Referring now to Fig. 2 and Fig. 3, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.

[0014] Fig. 2 illustrates a drivetrain (10) in a vehicle for achieving reduced wheelbase, according to an embodiment of the invention. In an embodiment, the drivetrain (10) includes a speed transmission unit (200), a range transmission unit (300), an intermediate driving shaft (102), an intermediate driving gear (104), an intermediate driven gear (106), an intermediate driven shaft (108), a differential pinion (402), a differential ring gear (404), a differential output shaft (500) and a rear axle (not shown). For the purpose of this description and ease of understanding, the drivetrain (10) is explained herein below with reference to be provided in an agricultural vehicle for achieving reduced wheelbase. However, it is also within the scope of the invention to use/practice the drivetrain (10) in any other vehicles without otherwise deterring the intended function of the drivetrain (10) as can be deduced from the description and corresponding drawings. [0015] The intermediate driving shaft (102) is rotatably coupled to a range output shaft (304), as shown in fig. 2) of the range transmission unit (300). For example, a front end (102F) of the intermediate driving shaft (102) is connected to the range output shaft (304). The intermediate driving shaft (102) is a hollow shaft. A portion of a power take-off shaft (PTO) shaft (10PTO), as shown in fig. 2) is disposed external to the intermediate driving shaft (102) and another portion of the PTO shaft (10PTO) is received by (inserted into) the intermediate driving shaft (102) and is rotatably connected to a crankshaft (not shown) of an engine. The intermediate driving shaft (102) is rotatably supported to a rear transmission housing (not shown) through a plurality of first bearings (103), as shown in fig. 2). One of the first bearing (103) is mounted onto the front end (102F), as shown in fig. 2) of the intermediate driving shaft (102), and another first bearing (103) is mounted onto the intermediate driving shaft (102) against a step portion (107), as shown in fig. 2) which is an integral part of the intermediate driving shaft (102). The range output shaft (304) is adapted to drive the intermediate driving gear (104) through the intermediate driving shaft (102). The intermediate driving gear (104) is rotatably mounted on a rear end (102R), as shown in fig. 2) of the intermediate driving shaft (102). The intermediate driving gear (104) drives the intermediate driven gear (106) when the intermediate driving gear (104) is driven by the range output shaft (304).

[0016] The intermediate driven gear (106) is rotatably mounted onto a rear end (108R), as shown in fig. 2) of the intermediate driven shaft (108) and is rotatably connected to the intermediate driving gear (104). The intermediate driven gear (106) is adapted to drive the differential pinion (402) through the intermediate driven shaft (108). The intermediate driven shaft (108) is disposed below and parallel to the intermediate driving shaft (102). The intermediate driven shaft (108) is rotatably supported to the rear transmission housing (not shown) through a pair of second bearings (105), as shown in fig. 2). The pair of second bearings (105) are mounted onto the intermediate driven shaft (108) and are located in between the intermediate driven gear (106) and the differential pinion (402). For the purpose of this description and ease of understanding, the intermediate driving gear (104) is considered to be a driving spur gear, and the intermediate driven gear (106) is considered to be a driven spur gear. However, it is also within the scope of the invention to provide other types of gears in place of spur gears without otherwise deterring the intended function of the intermediate driving gear (104) and the intermediate driven gear (106) as can be deduced from the description and corresponding drawings. [0017] The differential pinion (402) is rotatably mounted onto a front end (108F), as shown in fig. 2) of the intermediate driven shaft (108). The differential pinion (402) drives the differential ring gear (404) when the differential pinion (402) is driven by the intermediate driven gear (106). The differential pinion (402) is disposed in front of and spaced away from the intermediate driven gear (106). For the purpose of this description and ease of understanding, the differential pinion (402) is considered to be at least a spiral bevel pinion, and the differential ring gear (404) is considered to be a spiral bevel gear. The differential ring gear (404) is freely mounted onto the differential output shaft (500) and is rotatably connected to the differential pinion (402). The differential ring gear (404) is rotatably connected to a differential planetary gear set (not shown) which is mounted onto the differential output shaft (500). The rear axle (not shown) is parallel to the differential output shaft (500). The rear axle (not shown) is rotatably connected to the differential output shaft (500) through a pair of rear axle driving gears (not shown). For example, the rear axle driving gears (not shown) is mounted onto the rear axle and is meshed with the differential output shaft (500). For the purpose of this description and ease of understanding, the rear axle driving gears is considered to be a straight bevel gear set. The differential ring gear (404) is adapted to drive the differential output shaft (500) though the differential planetary gear set (not shown). The differential output shaft (500) is adapted to drive the rear axle (not shown) through the pair of rear axle driving gears (not shown). The rear axle (not shown) is adapted to drive the wheels of the vehicle when the rear axle (not shown) is driven by the differential output shaft (500) through rear axle driving gears. The differential ring gear (404) is also called a crown wheel. The differential ring gear (404) is disposed in front of the differential pinion (402) and is closer to the rear axle (not shown) The rear axle (not shown) is disposed in front of the differential output shaft (500) and is closer to the range transmission unit (300). Disposing the rear axle (not shown) closer to the range transmission unit (300) results in a reduction of the wheelbase of the vehicle. For example, a 70 mm reduction in wheelbase of the vehicle is achieved.

[0018] Further, a direction of power flow (P2), as shown in fig. 2) from the intermediate driven shaft (108) to the rear axle () is opposite to a direction of power flow (Pl), as shown in fig. 2) from the range output shaft (304) to the intermediate driving shaft (102). In an embodiment, a gear ratio of the intermediate driving gear (104) and the intermediate driven gear (106) is less than 1. [0019] Fig. 3 depicts a flowchart indicating steps of a method (700) of providing power flow in a drivetrain (10) of the vehicle, according to embodiments as disclosed herein. At step (702), the method (700) includes allowing power flow from a range output shaft (304) of a range transmission unit (300) to an intermediate driving gear (104) which is mounted onto an intermediate driving shaft (102). At step (704), the method (700) includes allowing power flow from the intermediate driving gear (104) to an intermediate driven gear (108) which is mounted onto a rear end (108R) of an intermediate driven shaft (106). At step (706), the method (700) includes allowing power flow to a differential pinion (402) which is mounted onto a front end (108F) of the intermediate driven shaft (108). At step (708), the method (700) includes allowing power flow from the differential pinion (402) to a differential ring gear (404) which is freely mounted onto a differential output shaft (500). At step (710), the method (700) includes, allowing power flow from the differential ring gear (404) to the differential output shaft (500) though a differential planetary gear set (not shown). At step (712), the method (700) includes allowing power flow from the differential output shaft (500) to the rear axle (not shown) through a pair of rear axle driving gears (not shown). At step (714), the method (700) includes allowing power flow from the rear axle to the wheels of the vehicle, wherein a direction of power flow (P2) from the intermediate driven shaft (108) to the rear axle (not shown) is opposite to a direction of power flow (Pl) from the range output shaft (304) to the intermediate driving shaft (102).

[0020] The technical advantages of the drivetrain (10) are as follows. The drivetrain (10) enables positioning of a rear axle closer to the range transmission unit thereby facilitating a reduced (shorter) wheelbase of the vehicle as well as achieves compact drivetrain with compact rear transmission housing and has simple and robust design.

[0021] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modifications within the spirit and scope of the embodiments as described herein.