CROSS REFERENCE TO RELATED APPLICATION

This Application is based on and derives the benefit of Indian Provisional Application 202211030614 filed on 27-May-2022, the contents of which are incorporated herein by reference.

TECHNICAL FIELD

[001] The embodiments herein generally relate to power transmission units in vehicles and more particularly, to a differential locking mechanism for an agricultural vehicle. Further, embodiments herein relate to a method for locking a differential member in a drivetrain of the vehicle.

BACKGROUND

[002] Agriculture has a tremendous need for tractors having various characteristics. This need has been met primarily by building a wide variety of tractors, including wheeled and tracked, of various heights and configurations. A differential unit is provided in the drivetrain of the vehicle for transmitting power from an engine to a drive axle as well as to allow wheels to rotate at different speeds from each other while the vehicle is taking turns. For example, the differential unit allows the inner wheels to rotate slower than the outer wheels while the vehicle is taking turns. Usually, a differential output shaft or a brake shaft in agricultural vehicles is locked by a locking member which is actuated by a foot operated differential locking pedal through linkages in which the differential locking pedal can be moved only in one direction by the operator (driver).

[003] Therefore, there exists a need for a differential locking mechanism for a vehicle, which obviates the aforementioned drawbacks.

OBJECTS

[004] The principal object of embodiments herein is to provide a differential locking mechanism for a vehicle. [005] Another object of embodiments herein is to provide the differential locking mechanism which allows a differential locking handle to be operated in both clockwise direction and anti-clockwise direction for locking a differential member or brake shaft.

[006] Another object of embodiments herein is to provide the differential locking mechanism, which enhances comfort level of operator.

[007] Another object of embodiments herein is to provide the differential locking mechanism, which is reliable and is easy to operate and is inexpensive.

[008] 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

[009] 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:

[0010] Fig. 1 depicts a perspective view of a differential locking mechanism for a vehicle, where the differential locking mechanism is in an unlocked position, according to embodiments as disclosed herein;

[0011] Fig. 2 depicts another perspective view of the differential locking mechanism in a locked position, according to embodiments as disclosed herein;

[0012] Fig. 3 depicts a side view of the differential locking mechanism, according to embodiments as disclosed herein;

[0013] Fig. 4 illustrates a fork shifting member positioned at intersection (meeting point) of a first face and a second face of a V-shaped groove of a shift fork when the differential locking mechanism is in the unlocked position, according to embodiments as disclosed herein; and

[0014] Fig. 5 depicts a flowchart indicating steps of a method for locking a differential member (brake shaft) in a drivetrain of the vehicle, according to embodiments as disclosed herein.

DETAILED DESCRIPTION

[0015] 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.

[0016] The embodiments herein achieve differential locking mechanism for a vehicle. Further, embodiments here in achieve a method for locking a differential member (brake shaft) in a drivetrain of the vehicle. Referring now to the drawings Figs 1 through 5, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.

[0017] Fig. 1 depicts a perspective view of the differential locking mechanism (100) for a vehicle, where the differential locking mechanism (100) is in an unlocked position, according to embodiments as disclosed herein. In an embodiment, the differential locking mechanism (100) includes a differential lock handle (102), a first lever (104), a linkage (106), a second lever (108), a shifting shaft (110), a spring (111), a fork shifting member (112), a spring retainer (113), a shift fork (114) and a differential locking member (116). For the purpose of this description and ease of understanding, the differential locking mechanism (100) is explained herein with below reference to locking a differential member (10P) in a drivetrain of the vehicle such as but not limited to an agricultural vehicle. However, it is also within the scope of the invention to use/practice the differential locking mechanism (100) is any other agricultural machines or any other off-road vehicles or any other vehicles or any other applications, where locking differential member (differential output shaft) is required, without otherwise deterring the intended function of the differential locking mechanism (100) as can be deduced from the description and corresponding drawings.

[0018] The differential locking handle (102) is movably coupled to the shifting shaft (110) through a plurality of linkages (104, 106, 108). The first lever (104), the second lever (108), and the linkage (106) constitute the plurality of linkages (104, 106, 108). The differential locking handle (102) is rotatably mounted onto a pivot pin (103), as shown in fig. 2) through the first lever (104). The pivot pin (103) is connected to a differential housing (not shown). The first lever (104) is adapted to connect the differential locking handle (102) to one end of the linkage (106). The first lever (104) is connected to the differential locking handle (102). The first lever (104) includes a first sleeve (104S), as shown in fig. 3) rotatably mounted onto the pivot pin (103) of the vehicle. Further, the first lever (104) includes a first arm (104A), as shown in fig. 3) extending from the first sleeve (104S) and is connected to one end of the linkage (106). The second lever (108) is adapted to connect the linkage (106) to the shifting shaft (110). The second lever (108) is connected to the shifting shaft (110). The second lever (108) includes a second sleeve (108S), as shown in fig. 3 and fig. 4) adapted to be mounted onto one end of the shifting shaft (110). Further, the second lever (108) includes a second arm (108A) extending from the sleeve (108S) and is connected to another end of the linkage (106). The linkage (106) is adapted to connect the first lever (104) to the second lever (108) thereby connecting the differential locking handle (102) to the shifting shaft (110). One end of the linkage (106) is connected to the first lever (104) and another end of the linkage (106) is connected to the second lever (108).

[0019] One end of the shifting shaft (110) is rotatably mounted onto the differential housing (not shown) of the vehicle. The fork shifting member (112) defined on the shifting shaft (110). The shift fork (114) is slidably connected to the shifting shaft (110) and is engaged against the fork shifting member (112). The shift fork (114) includes a head (114H) and a body (114B), as shown in fig. 3 and fig. 4). The body (114B) extends between the head (114H) of the shift fork (114) and the differential locking member (116). In an embodiment, the head (114H) of the shift fork (114) defines a shaft receiving portion (114R), as shown in fig. 4) and a V-shaped groove (114V), as shown in fig. 1 and fig. 4). The shaft receiving portion (114R) of the head (114H) is adapted to receive the shifting shaft (110) therethrough. The V-shaped groove (114V) defines a first face (114F), as shown in fig. 1, fig. 2 and fig. 4) and a second face (114S), as shown in fig. 4). [0020] The V shaped groove (114V) facilitates rotation of the differential lock handle (102) in one of a clockwise direction and an anti-clockwise direction. The fork shifting member (112) is transmitting the force on either of the first face (114F) or the second face (114S) of the V shaped groove (114V) when the differential locking handle (102) is being rotated in one of the clockwise direction or the anti-clockwise direction respectively. The spring (111) is adapted to load the V-shaped groove (114V) of the shift fork (114) against the fork shifting member (112). One end of the spring (111) is engaged with the spring retainer (113) which is located on the shifting shaft (110), and another end of the spring (111) is engaged with the head (114H) of the shift fork (114) thereby engaging (loading) the V-shaped groove (114V) against the fork shifting member (112). The spring retainer (113) is an integral part of the shifting shaft (110) or a separate part that is mounted onto the shifting shaft (110).

[0021] The differential locking member (116) is connected to the shift fork (114). The differential locking member (116) is adapted to be moved between one of a locked position (as shown in fig. 2) or an unlocked position (as shown in fig.l and fig. 4). In the locked position, the differential locking member (116) is engaged with the differential member (10P) thereby locking the differential member (10P) upon pushing or pulling the differential locking handle (102). In the unlocked position, the differential locking member (116) is dis-engaged from the differential member (10P) thereby unlocking the differential member (10P) upon releasing the differential locking handle (102). For the purpose of this description and ease of understanding, the differential locking member (116) is considered to be a sleeve, and the differential member (10P) is considered to be a differential output shaft or brake shaft. The differential locking member (116) defines a plurality of first locking elements (116S), as shown in fig. 3 and fig. 4) corresponding to a plurality of second locking elements (10S), as shown in fig. 1) defined on the differential member (10P). The first locking elements (116S) of the differential locking member (116) is engaged with the second locking elements (10S) of the differential member (10P) thereby locking the differential member (10P) when the differential locking member (116) is in the locked position. The first locking elements (116S) of the differential locking member (116) is disengaged from the second locking elements (10S) of the differential member (10P) thereby unlocking the differential member (10P) when the differential locking member (116) is in the unlocked position. For the purpose of this description and ease of understanding, the first locking elements (116S) of the differential locking member (116) are at least internal splines (internal gear teeth), and the second locking elements (10S) of the differential member (10P) are at least external splines (external gear teeth). [0022] The fork shifting member (112) is adapted to slide over one of the first face (114F) or the second face (114S) of the V-shaped groove (114V) thereby moving the differential locking member (116) through the shift fork (114) to the locked position upon pulling or pushing the differential locking handle (102) respectively. The fork shifting member (112) is positioned at intersection (meeting point) of the first face (114F) and the second face (114S) when the differential locking member (116) is in the unlocked position. For the purpose of this description and ease of understanding, the fork shifting member (112) is considered to be a pin which is transversely mounted onto said shifting shaft (110). The spring (111) is adapted to move the shift fork (114) to its initial position thereby moving the differential locking member (116) to the unlocked position upon releasing the differential locking handle (102).

[0023] When there is a requirement to lock the differential member (10P), the operator can either pull or push the differential locking handle (102) for locking the differential member (10P). When the operator pulls the differential locking handle (102), the first lever (104) pulls the second lever (108) by pulling the linkage (106). On pulling the second lever (108), the shifting shaft (110) rotates in a clockwise direction to allow the fork shifting member (112) to slide on the first face (114F) of the V-shaped groove (114V) thereby moving the differential locking member (116) through the shift fork (114) to the locked position.

[0024] When the operator pushes the differential locking handle (102), the first lever (104) pushes the second lever (108) by pushing the linkage (106). On pushing the second lever (108), the shifting shaft (110) rotates in an anti-clockwise direction to allow the fork shifting member (112) to slide on the second face (114F) of the V-shaped groove (114V) thereby moving the differential locking member (116) through the shift fork (114) to the locked position.

[0025] Fig. 5 depicts a flowchart (200) indicating steps of a method (200) for locking a differential member (10P) in a drivetrain of a vehicle, according to embodiments as disclosed herein. At step (202), the method (200) includes, rotating, by a differential locking handle (102), a shifting shaft (110) through a plurality of linkages (104, 106, 108) in one a first predefined direction or a second predefined direction upon pulling or pushing the differential locking handle (102) respectively. Ats step (204), the method (200) includes moving, by a fork shifting member (112), a differential locking member (116) through a shift fork (114) to a locked position in which a plurality of first locking elements (116S) of the differential locking member (116) is engaged with a plurality of second locking elements (IOS) of the differential member (10P) thereby locking the differential member (10P) when the shifting shaft (110) is rotated by the differential locking handle (102). The first predefined direction in which the shifting shaft (110) is being rotated by the differential locking handle (102) is considered to be clockwise direction. The second predefined direction in which the shifting shaft (110) is being rotated by the differential locking handle (102) is considered to be anti-clockwise direction.

[0026] At step (208), the method (200) includes, moving, by a spring (111), the shift fork (114) to its initial position thereby moving the differential locking member (116) from the locked position to an unlocked position in which the first locking elements (116S) of the differential locking member (116) is disengaged from the second locking elements (10S) of the differential member (10P) thereby unlocking the differential member (10P) upon releasing the differential locking handle (102).

[0027] The method step (204) includes, sliding, by the fork shifting member (112), over one of a first face (114F) or a second face (114S) defined on a V-shaped groove (114V) of the shift fork (114) thereby moving the differential locking member (116) through the shift fork (114) to the locked position when the shifting shaft (110) is rotated by the differential locking handle (102) in one of the first predefined direction or the second predefined direction respectively.

[0028] The technical advantages of the differential locking mechanism (100) are as follows. The differential locking mechanism (100) is reliable and is easy to operate and is inexpensive. Operator will have flexibility to operate the differential locking handle and operator doesn’t need to remember its actuating direction for fail safe operation. The differential locking mechanism allows the differential locking handle to be rotated in both clockwise direction and anti-clockwise direction for locking the differential member in the drivetrain of the vehicle.

[0029] 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.