The following specification particularly describes the invention and the manner in which it is to
be performed.
2
TECHNICAL FIELD
Present disclosure, in general, relates to the field of automobiles. Particularly, but not
exclusively, the present disclosure relates to lubrication of a gearbox assembly. Further,
embodiments of the present disclosure relate to a lubrication system for the gearbox assembly
in the vehicle and the gearbox assembly thereof.
BACKGROUND OF THE DISCLOSURE
Lubrication may be referred to as a process of channelizing lubricant between two or more
moving components to reduce frictional engagement therebetween. Failure to lubricate the
5 components of a vehicle may damage the moving components partially or completely. There
are several moving components in the vehicle which require lubrication.
Conventionally, assemblies such as a gearbox assembly in the vehicles, which may be cascaded
to prevent access to internal components, may often be filled with an oil for lubrication. The
10 gearbox assembly may be lubricated by different lubrication methods such as, greased
lubrication, splash lubrication, forced oil lubrication and the like. In general, splash lubrication
is often employed in the gearbox where oil is splashed by a plurality of gears of the gearbox
assembly and the splashed oil may lubricate the components of the gearbox. In such scenarios
where the oil may be splashed, the oil may not be uniformly distributed across the gearbox to
15 each component. Further, the gearbox assembly may include one or more gears with small
diameter, where the oil splashed by such gears may not reach a component proximal to the
gears.
To overcome insufficient lubrication within the gearbox, forced oil lubrication systems are
20 used, where one or more pumps may pump the oil to the gearbox. However, the pumps require
supply of power and may make the vehicle bulky. Furthermore, forced oil lubrication may not
be economical.
The present disclosure is directed to overcome one or more limitations stated above or any
25 other limitations associated with the conventional mechanisms.
SUMMARY OF THE DISCLOSURE
One or more shortcomings of the prior art are overcome by a method and a system as claimed
30 and additional advantages are provided through the method and the system as claimed in the
present disclosure. Additional features and advantages are realized through the techniques of
3
the present disclosure. Other embodiments and aspects of the disclosure are described in detail
herein and are considered a part of the claimed disclosure.
In one non-limiting embodiment of the present disclosure a lubrication system for a gearbox
5 assembly is disclosed. The lubrication system comprises at least one shifter sleeve, at least one
shifter fork and at least one oil duct. The at least one shifter sleeve is slidably disposed on at
least one gear shaft of a gearbox. The at least one shifter fork is connected to a shifter shaft,
the at least one shifter fork being configured to receive the at least one shifter sleeve. The at
least one oil duct is fluidly connected to the at least one shifter fork and is structured to extend
10 between the at least one shifter sleeve and an output section of the gearbox. The at least one oil
duct is configured to receive oil from the at least one shifter fork and to direct the oil into the
output section of the gearbox.
In an embodiment, the at least one shifter fork and the at least one shifter sleeve define a first
15 channel configured to guide the oil to the at least one shifter sleeve, from a casing of the
gearbox by at least one pair of gears.
In an embodiment, the at least one shifter fork and the at least one oil duct define a second
channel along a portion of the casing, to convey the oil.
20
In an embodiment, the at least one shifter fork is defined with at least one aperture to receive
the oil from the first channel and allow flow of the oil to the at least one oil duct to define the
second channel.
25 In an embodiment, the at least one shifter sleeve is defined with a passage along at least a
portion of circumference of the at least one shifter sleeve to receive the oil during operation of
the at least one pair of gears in the gearbox.
In an embodiment, the at least one shifter fork is defined with at least one guideway tangential
30 to the passage defined on the at least one shifter sleeve to receive and guide the oil from the
first channel to the second channel through the at least one aperture.
In an embodiment, the at least one guideway is defined with gradually decreasing diameter to
supply pressurized flow of the oil towards the at least one aperture.
35
4
In an embodiment, the at least one aperture is defined at one end of the at least one guideway
of the at least one shifter fork to allow flow of the oil from the first channel to the second
channel.
5 In an embodiment, the at least one oil duct and at least one rear casing define a third channel
that is configured to receive the oil from the second channel to lubricate the output section of
the gearbox.
In an embodiment, the at least one oil duct is positioned at a gradient relative to length of the
10 casing.
In an embodiment, a portion of at least one rear casing defines a return channel along length of
the gearbox assembly for re-circulation of the oil from the output section to the casing, and
wherein the at least one rear casing comprises a bushing to house the output shaft and a
15 propeller shaft and defined with a plurality of grooves to allow flow of the oil from the third
channel to the return channel.
In an embodiment, the second channel is defined extending along length wise direction of the
casing of the gearbox assembly.
20
In an embodiment, the at least one pair of gears are positioned proximal to the output shaft of
the gearbox assembly. The at least one pair of gears comprises a first gear and a second gear.
The first gear is positioned on the at least one gear shaft. The second gear is positioned on the
output shaft, wherein diameter of the first gear is less than diameter of the second gear.
25
In another non-limiting embodiment, a gearbox assembly for a vehicle is disclosed. the gearbox
assembly comprises a casing, at least one rear casing, at least one shifter sleeve, at least one
shifter fork and a lubrication system. The casing is configured to accommodate at least one
gear shaft, where the at least one gear shaft is configured to accommodate at least one pair of
30 gears. The at least one rear casing is defined on one end of the casing configured to
accommodate an output shaft. The at least one shifter sleeve is slidably disposed on the at least
one gear shaft. The at least one shifter fork is connected to a shifter shaft and is configured to
receive the at least one shifter sleeve. The lubrication system fluidly connects the at least one
shifter sleeve, the at least one pair of gears, and the at least one shifter fork. The lubrication
35 system comprises at least one oil duct fluidly connected to the at least one shifter fork. The at
least one oil duct is structured to extend between the at least one shifter sleeve and an output
5
section of a gearbox and is configured to receive oil from the at least one shifter fork and direct
the oil into the output section of the gearbox.
In an embodiment, the at least one shifter fork and the at least one shifter sleeve define a first
5 channel configured to guide the oil to the at least one shifter sleeve, from a casing of the
gearbox by the at least one pair of gears.
In an embodiment, the at least one shifter fork and the at least one oil duct define a second
channel along a portion of the casing to convey the oil.
10
In an embodiment, the at least one oil duct and the at least one rear casing define a third channel
that is configured to receive the oil from the second channel to lubricate the output section.
In an embodiment, a portion of the at least one rear casing defines a return channel along length
15 of the gearbox assembly for re-circulation of the oil from the output section to the casing, and
wherein the at least one rear casing comprises a bushing to house the output shaft and a
propeller shaft and defined with a plurality of grooves to allow flow of the oil from the third
channel to the return channel.
20 In an embodiment, the at least one shifter fork is defined with at least one aperture to receive
the oil from the first channel and allow flow of the oil to the at least one oil duct to define the
second channel.
The foregoing summary is illustrative only and is not intended to be in any way limiting. In
25 addition to the illustrative aspects, embodiments, and features described above, further aspects,
embodiments, and features will become apparent by reference to the drawings and the
following detailed description.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
30
The novel features and characteristic of the disclosure are set forth in the appended claims. The
disclosure itself, however, as well as a preferred mode of use, further objectives and advantages
thereof, will best be understood by reference to the following detailed description of an
illustrative embodiment when read in conjunction with the accompanying figures. One or more
35 embodiments are now described, by way of example only, with reference to the accompanying
figures wherein like reference numerals represent like elements and in which:
6
Figure 1 is an isometric inside view of a gearbox assembly, in accordance with an embodiment
of the present disclosure.
Figure 2a is an isometric view of a lubrication system for a gearbox assembly in a vehicle in
5 accordance with an embodiment of the present disclosure.
Figure 2b is an isometric view of the lubrication system for the gearbox assembly depicting a
plurality of oil channels, in accordance with an embodiment of the present disclosure.
10 Figure 2c is a front view of the lubrication system for the gearbox assembly depicting a first
channel, in accordance with an embodiment of the present disclosure.
Figure 3a is a top sectional view of a rear casing depicting a plurality of grooves, in accordance
with an embodiment of the present disclosure.
15
Figure 3b is a top sectional view of a rear casing depicting a third channel and a return channel,
in accordance with an embodiment of the present disclosure.
The figures depict embodiments of the disclosure for purposes of illustration only. One skilled
20 in the art will readily recognize from the following description that alternative embodiments of
the system and method illustrated herein may be employed without departing from the
principles of the disclosure described herein.
DETAILED DESCRIPTION
25
While the embodiments in the disclosure are subject to various modifications and alternative
forms, specific embodiment thereof has been shown by way of example in the figures and will
be described below. It should be understood, however that it is not intended to limit the
disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all
30 modifications, equivalents, and alternative falling within the scope of the disclosure.
The terms “comprises”, “comprising”, or any other variations thereof used in the disclosure,
are intended to cover a non-exclusive inclusion, such that a device, assembly, mechanism,
system, that comprises a list of components does not include only those components but may
35 include other components not expressly listed or inherent to such system, or assembly, or
device. In other words, one or more elements in a system proceeded by “comprises… a” does
7
not, without more constraints, preclude the existence of other elements or additional elements
in the system or method.
Embodiments of the present disclosure discloses a lubrication system for a gearbox assembly
5 is disclosed. The lubrication system comprises at least one shifter sleeve, at least one shifter
fork and at least one oil duct. The at least one shifter sleeve is slidably disposed on at least one
gear shaft of a gearbox. The at least one shifter fork is connected to a shifter shaft, the at least
one shifter fork being configured to receive the at least one shifter sleeve. The at least one oil
duct is fluidly connected to the at least one shifter fork and is structured to extend between the
10 at least one shifter sleeve and an output section of the gearbox. The at least one oil duct is
configured to receive oil from the at least one shifter fork and to direct the oil into the output
section of the gearbox. With such configuration, the lubrication system may lubricate the output
section of the gearbox in a vehicle and may reduce or eliminate damage due to insufficient
lubrication of the gearbox. The first channel, the second channel, the third channel and the
15 return channel defined in the gearbox assembly may refer to portions of flow path of the oil in
the gearbox of the gearbox assembly and may not be considered to be components of the
gearbox.
The disclosure is described in the following paragraphs with reference to Figures 1 to 3b. In
20 the figures, the same element or elements which have same functions are indicated by the same
reference signs. It is to be noted that, the vehicle is not illustrated in the figures for the purpose
of simplicity. One skilled in the art would appreciate that the system and assembly as disclosed
in the present disclosure may be used in any vehicle including but not liming to heavy and light
commercial vehicles, load carrying vehicles, passenger vehicles, and the like. The system and
25 the method of the present disclosure may also be implemented in vehicles having manual
transmission or automatic transmission, for suitably lubricating the gearbox without deviating
from the principles of the present disclosure.
Figure 1 refers to an exemplary embodiment of the present disclosure which illustrates a
30 gearbox assembly (100) of a vehicle [not shown in Figures]. The gearbox assembly (100) may
include a gearbox (101) which is operatively connectable to an engine [not seen in figures] of
the vehicle. The gearbox (101) may include a casing (1) configured to enclose a plurality of
gears rotatably disposed on at least one gear shaft (2). Further, a portion of the casing (1) may
be configured to store oil to lubricate components of the gearbox (101). In an embodiment, the
8
oil may be stored at a bottom portion of the casing (1) of the gearbox (101) in an oil sump [not
shown].
The gearbox (101) may include an input shaft (17) connectable to the engine and an output
5 shaft (5) connectable to a plurality of wheels [not seen in figures] of the vehicle, where the
input shaft (17) and the output shaft (5) may be rotatably engaged through the plurality of gears.
The gearbox (101) may include at least one lay shaft connectable between the input shaft (17)
and the output shaft (5). In an embodiment, a gear of the plurality of gears (3) may be mounted
on at least one of the input shaft (17), the output shaft (5) and the at least one layshaft. In an
10 embodiment, at least one pair of gears (3) of the plurality of gears may splash the oil, where at
least a portion of the at least one pair of gears (3) may be immersed in the oil. In an embodiment,
the at least one pair of gears (3) of the plurality of gears may include a first gear [not explicitly
shown in figures] on the at least one layshaft and a second gear (3a) on at least one of the input
shaft (17) and the output shaft (5). The diameter of the first gear may be less than that of the
15 second gear (3a). Therefore, a portion of oil splashed by the first gear that reaches the output
section (14) may not be sufficient to lubricate the output section (14).
Referring now to Figures 2a, 2b and 2c, the gearbox assembly (100) may include a lubrication
system (200). The lubrication system (200) may include at least one shifter sleeve (4) slidably
20 disposed on at least one gear shaft (2). The at least one shifter sleeve (4) may be configured to
slide along the at least one gear shaft (2) and between at least two gears of the plurality of gears
of the gearbox (101). The at least one shifter sleeve (4) may be defined with an inner portion
and an outer portion, where the inner portion may be defined with a plurality of teeth to engage
with the plurality of gears. In an embodiment, the at least one shifter sleeve (4) may rotate
25 about the at least one gear shaft (2) upon engaging with at least one gear of the plurality of
gears. The outer portion of the at least one shifter sleeve (4) may be defined with a first passage
(201) along at least a portion of circumference of the outer portion. The first passage (201) may
collect the oil splashed by the at least one pair of gears (3) due to rotation of at least one of the
first gear and the second gear (3a). The at least one shifter sleeve (4) may carry the oil splashed
30 by the at least one pair of gears (3) by centrifugal force during rotation about the at least one
gear shaft (2).
Further, the gearbox assembly (100) may include a shifter shaft (6) disposed within and along
length of the gearbox (101). The gearbox (101) may include at least one shifter fork (7)
35 connected to the shifter shaft (6), where the at least one shifter fork (7) being configured to
9
receive the at least one shifter sleeve (4). The at least one shifter fork (7) may be defined with
a curved profile to receive the at least one shifter sleeve (4). In an embodiment, the at least one
shifter fork (7) may be defined with a semicircular profile, defined with two ends such as a first
end (7a) and a second end (7b), where the at least one shifter fork (7) may receive the at least
5 one shifter sleeve (4) between the two ends. The at least one shifter fork (7) may be defined
with at least one guideway (9) tangential to the first passage (201) of the at least one shifter
sleeve (4) and may be extending toward the second end (7b). The at least one guideway (9)
may receive and guide the oil from the first passage (201) of the at least one shifter sleeve (4)
towards the second end (7b) of the at least one shifter fork (7) as best seen in Figure 2b.
10
Referring again to Figure 2b, the at least one shifter fork (7) may be defined with at least one
aperture (10) proximal to the second end (7b) of the at least one shifter fork (7). In an
embodiment, the at least one shifter sleeve (4) and the at least one shifter fork (7) define a first
channel (201) to guide the oil from casing (1) to the at least one aperture (10). In the illustrative
15 embodiment, the first channel (201) may be defined between the first end (7a) of the at least
one shifter fork (7), and the at least one aperture (10). In an embodiment, the at least one
guideway (9) may be defined with a gradually decreasing diameter to supply pressurized oil
from the first passage (201) to the at least one aperture (10). In an embodiment, the at least one
guideway (9) may be defined with smaller diameter proximal to the second end (7b) compared
20 to the diameter proximal to the first end (7a) of the at least one shifter fork (7). The at least one
shifter fork (7) may receive the oil from the at least one shifter sleeve (4) and may guide the
oil through the first passage (201) and the at least one aperture (10) as can be seen in Figure
2b.
25 Referring again to Figures 1 and 2b, the lubrication system (200) may include at least one oil
duct (8) fluidly connected to the at least one shifter fork (7) and may be structured to extend
between the at least one shifter sleeve (4) and an output section (14) of the gearbox (101) as
can be seen in Figure 1. In an embodiment, the output section (14) of the gearbox (101) may
include the output shaft (5). The output shaft (5) may be supported by a bushing (12) and at
30 least one rear casing (1’), where a propeller shaft [not shown in figures] may rotate in the
bushing (12). The at least one rear casing (1’) may be positioned at the output section (14) of
the gearbox (101) and away from the casing (1) along lengthwise direction of the gearbox
(101). The at least one rear casing (1’) may be configured to accommodate the output shaft (5)
and the bushing (12). In an embodiment, the output shaft (5) may extend from the at least one
10
rear casing (1’) to be connectable to the plurality of wheels of the vehicle through the propeller
shaft. In an embodiment, the at least one oil duct (8) may receive oil from the at least one shifter
fork (7) and may direct the oil into the output section (14) of the gearbox (101). In an
embodiment, the at least one oil duct (8) may receive the oil from the first channel (201)
5 through the at least one aperture (10) of the at least one shifter fork (7). The at least one oil
duct (8) may be connected to a portion of the casing (1) and may be positioned proximal to the
at least one aperture (10) of the at least one shifter fork (7). The at least one oil duct (8) may
extend along length of the casing (1) of the gearbox (101). The at least one oil duct (8) may be
defined with a tube shaped profile to receive and guide the oil from the at least one aperture
10 (10) of the at least one shifter fork (7). For sake of illustration, the profile of the at least one oil
duct (8) is depicted as a rectangular profile where, the top end is open to the gearbox (101) to
receive the oil and the same shall not be considered a limitation.
In an embodiment, the at least one oil duct (8) may be defined with a projection (8a) defined
15 proximal to the at least one aperture (10) and extending from the at least one oil duct (8) towards
the at least one aperture (10), to receive the pressurized oil from the at least one aperture (10)
and may prevent flow of oil away from the at least one oil duct (8). In an embodiment, length
of the at least one projection (8a) may be defined to collect the oil from the at least one aperture
(10), even when the at least one shifter fork (7) may be displaced between two gears of the
20 plurality of gears. For example, length of the at least one projection (8a) may be defined such
that the at least one projection (8a) extends between two adjacent gears of the plurality of gears.
The at least one oil duct (8) may be positioned at a gradient relative to length of the casing (1)
to guide the oil from the at least one aperture (10) to the output section (14) of the gearbox
25 (101). The oil may flow towards the output section (14) of the gearbox (101) from the at least
one oil duct (8) due to at least one of the pressurized flow and in addition to gravity and gradient
of the at least one oil duct (8). Further, the at least one shifter fork (7) and the at least one oil
duct (8) define a second channel (202) along a portion of the casing (1), to convey the oil. The
second channel (202) may be defined between the exit of the at least one aperture (10) of the
30 at least one shifter fork (7) and to the output section (14) of the gearbox (101).
Referring now to Figures 2a and 2c, the gearbox (101) may include an oil receiver (13)
positioned at the end of the at least one oil duct (8) and fluidly connected to the output section
(14) of the gearbox (101). The oil receiver (13) may receive the oil from the at least one oil
35 duct (8), may store the oil and may guide the oil to the output section (14) of the gearbox (101).
11
In an embodiment, the oil receiver (13) may be defined with a tube shaped profile to receive
the oil. In specific, cross section of the oil receiver (13) may have a rectangular shape. In the
illustrative embodiment, the second channel (202) may be defined between exit of the at least
one aperture (10) and exit of the oil receiver (13).
5
Referring now to Figures 1, 3a and 3b, the output section (14) of the gearbox (101) may include
a second passage (15) and a third passage (16) defined along the at least one rear casing (1’) of
the gearbox (101). The output shaft (5) may rotate relative to the bushing (12) upon engagement
of the at least one pair of gears (3) of the gearbox (101) to drive the plurality of wheels through
10 the propeller shaft, which slides over external splines of the output shaft (5). In an embodiment,
the second passage (15) may be defined along length of the at least one rear casing (1’)
substantially parallel to a rotation axis of the output shaft (5) as can be seen in Figures 3a and
3b. The second passage (15) may be defined with a downward gradient towards the bushing
(12) of the output shaft (5), where the oil from the oil receiver (13) may be guided to flow from
15 the at least one rear casing (1’) to the bushing (12) due to the downward gradient. The second
passage (15) may be configured to receive the oil from the second channel (202) where the
second passage (15) may be fluidly connected to the oil receiver (13) as can be seen in Figure
1. The oil from the oil receiver (13) may be guided by the second passage (15) to the output
shaft (5) of the gearbox (101). In an embodiment, the at least one oil duct (8) and at least one
20 rear casing (1’) may define a third channel (203) to receive the oil from the second channel
(202) to lubricate the output section (14). The third channel (203) may be defined between exit
of the at least one oil duct (8) and the at least one rear casing (1’). The oil may lubricate interface
between the bushing (12) and the propeller shaft [not shown in figures], between the propeller
shaft and the output shaft (5), and between the output shaft (5) and the oil seal lip (18), where
25 the oil splashed by the at least one pair of gears (3) may not be sufficient to lubricate the output
section (14). The oil reaching the bushing (12) may form an oil film between the bushing (12)
and the propeller shaft, whose internal splines will mesh with the external splines of output
shaft (5). The oil reaching the bushing (12) may also lubricate the oil seal lip (18) and the output
shaft (5). Thus, the lubrication system (200) may eliminate or reduce damage to the output
30 section (14) of the gearbox (101) due to insufficient lubrication from the splashing.
Further, the at least one rear casing (1’) may be defined with a third passage (16) defined along
length of the gearbox (101) and may be defined between the output section (14) and the casing
(1) of the gearbox (101). Further, the bushing (12) may be defined with a plurality of grooves
12
(11) fluidly connected to the third channel (203) configured to receive the oil from the third
channel (203). The plurality of grooves (11) may be fluidly coupled to the third passage (16)
to guide the oil from the at least one rear casing (1’) to the third passage (16). In an embodiment,
a portion of the at least one rear casing (1’) may define a return channel (204) for re-circulation
5 of the oil from the output shaft (5) from the at least one rear casing (1’) to the casing (1). In an
embodiment, the return channel (204) may be defined from exit of the second passage (15) to
exit of the at least one rear casing (1’) connected to the casing (1) of the gearbox (101). Thus,
the return channel (204) may re-circulate the oil from the second channel (202) through the
plurality of grooves (11) and the third passage (16) back to the casing (1) of the gearbox (101).
10 In an embodiment, the oil may flow along the second passage (15) due to gravity and may flow
along the third passage (16) due to at least one of rotation of the output shaft (5) and gravity.
The re-circulated oil may then be splashed by the at least one pair of gears (3), thus ensuring
lubrication of the output section (14).

15 In an embodiment, when the at least one pair of gears (3) are engaged by the at least one shifter
sleeve (4), the at least one shifter sleeve (4) may draw oil splashed by the at least one pair of
gears (3) to the first channel (201). In an embodiment, the first channel (201) may be defined
along at least a portion of the at least one shifter sleeve (4) and the at least one shifter fork (7).
The at least one shifter fork (7) may pressurize the oil received from the at least one shifter
20 sleeve (4) and may guide the oil to the second channel (202) to lubricate the output section (14)
of the gearbox (101). In an embodiment, the second channel (202) may be defined along a
portion of the at least one oil duct (8).
The second passage (15) may receive the oil from the second channel (202) to lubricate the
25 output section (14). In an embodiment, the third channel (203) may be defined along at least a
portion of the second passage (15).
In an embodiment, the shifter fork may be defined with at least one flap covering at least a
portion of the at least one shifter sleeve (4) to collect the oil splashed by the at least one pair of
30 gears (3).
In an embodiment, the at least one oil duct (8) may be integrally defined in the gearbox (101)
of the gearbox assembly (100).
13
In an embodiment, the lubrication system (200) may lubricate the output section (14) of the
gearbox (101) in a vehicle and may reduce or eliminate damage due to insufficient lubrication
of the gearbox (101).
5 In an embodiment, the lubrication system (200) may require minimal modification to
components of the gearbox assembly (100) and may be cost effective due to minimal
modifications. For example, the shifter fork of the present disclosure does not require to be
provided with complex and intricately designed parts. Further, the shifter shaft (6) may be
maintained as a solid shaft, as in typical gearbox systems, and need not be made a hollow shaft
10 for collecting or conveying oil.
In an embodiment, the lubrication system (200) may pressurize flow of the oil, ensuring
sufficient lubrication for components of the gearbox (101).
15 EQUIVALENTS
With respect to the use of substantially any plural and/or singular terms herein, those having
skill in the art can translate from the plural to the singular and/or from the singular to the plural
as is appropriate to the context and/or application. The various singular/plural permutations
20 may be expressly set forth herein for sake of clarity.
It will be understood by those within the art that, in general, terms used herein, and especially
in the appended claims (e.g., bodies of the appended claims) are generally intended as “open”
terms (e.g., the term “including” should be interpreted as “including but not limited to,” the
25 term “having” should be interpreted as “having at least,” the term “includes” should be
interpreted as “includes but is not limited to,” etc.). It will be further understood by those
within the art that if a specific number of an introduced claim recitation is intended, such an
intent will be explicitly recited in the claim, and in the absence of such recitation no such intent
is present. For example, as an aid to understanding, the following appended claims may
30 contain usage of the introductory phrases “at least one” and “one or more” to introduce claim
recitations. However, the use of such phrases should not be construed to imply that the
introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular
claim containing such introduced claim recitation to inventions containing only one such
recitation, even when the same claim includes the introductory phrases “one or more” or “at
35 least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be
interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite
14
articles used to introduce claim recitations. In addition, even if a specific number of an
introduced claim recitation is explicitly recited, those skilled in the art will recognize that such
recitation should typically be interpreted to mean at least the recited number (e.g., the bare
recitation of “two recitations,” without other modifiers, typically means at least two recitations,
5 or two or more recitations). Furthermore, in those instances where a convention analogous to
“at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense
one having skill in the art would understand the convention (e.g., “a system having at least one
of A, B, and C” would include but not be limited to systems that have A alone, B alone, C
alone, A and B together, A and C together, B and C together, and/or A, B, and C together,
10 etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is
used, in general such a construction is intended in the sense one having skill in the art would
understand the convention (e.g., “a system having at least one of A, B, or C” would include but
not be limited to systems that have A alone, B alone, C alone, A and B together, A and C
together, B and C together, and/or A, B, and C together, etc.). It will be further understood by
15 those within the art that virtually any disjunctive word and/or phrase presenting two or more
alternative terms, whether in the description, claims, or drawings, should be understood to
contemplate the possibilities of including one of the terms, either of the terms, or both
terms. For example, the phrase “A or B” will be understood to include the possibilities of “A”
or “B” or “A and B.”
20
In addition, where features or aspects of the disclosure are described in terms of Markush
groups, those skilled in the art will recognize that the disclosure is also thereby described in
terms of any individual member or subgroup of members of the Markush group.
25 While various aspects and embodiments have been disclosed herein, other aspects and
embodiments will be apparent to those skilled in the art. The various aspects and embodiments
disclosed herein are for purposes of illustration and are not intended to be limiting, with the
true scope and spirit being indicated by the following claims.
30 Referral Numerals:
Component Referral
numeral
Gearbox assembly 100
Lubrication system 200
Casing 1
At least one rear casing 1’
15
At least one gear shaft 2
At least one pair of gears 3
Second gear 3a
At least one shifter sleeve 4
First passage 4’
Output shaft 5
Shifter shaft 6
At least one shifter fork 7
First end 7a
Second end 7b
At least one oil duct 8
At least one projection 8a
At least one guideway 9
At least one aperture 10
Plurality of grooves 11
Bushing 12
Oil receiver 13
Output section 14
Second passage 15
Third passage 16
Input shaft 17
Oil seal lip 18
Gearbox 101
First channel 201
Second channel 202
Third channel 203
Return channel 204

16
We Claim:
1. A lubrication system (200) for a gearbox assembly (100) of a vehicle, the system (200)
comprising:
at least one shifter sleeve (4) slidably disposed on at least one gear shaft (2) of
5 a gearbox (101);
at least one shifter fork (7) connected to a shifter shaft (6), the at least one shifter
fork (7) being configured to receive the at least one shifter sleeve (4); and
at least one oil duct (8) fluidly connected to the at least one shifter fork (7), the
at least one oil duct (8) being structured to extend between the at least one shifter sleeve
10 (4) and an output section (14) of the gearbox (101), the at least one oil duct (8) being
configured to receive oil from the at least one shifter fork (7) and to direct the oil into
the output section (14) of the gearbox (101).
2. The lubrication system (200) as claimed in claim 1, wherein the at least one shifter fork
15 (7) and the at least one shifter sleeve (4) define a first channel (201) configured to guide
the oil to the at least one shifter sleeve (4), from a casing (1) of the gearbox (101) by at
least one pair of gears (3).
3. The lubrication system (200) as claimed in claim 2, wherein the at least one shifter fork
20 (7) and the at least one oil duct (8) define a second channel (202) along a portion of the
casing (1), to convey the oil.
4. The lubrication system (200) as claimed in claim 3, wherein the at least one shifter fork
(7) is defined with at least one aperture (10) to receive the oil from the first channel
25 (201) and allow flow of the oil to the at least one oil duct (8) to define the second
channel (202).
5. The lubrication system (200) as claimed in claim 2, wherein the at least one shifter sleeve
(4) is defined with a passage along at least a portion of circumference of the at least one
30 shifter sleeve (4) to receive the oil during operation of the at least one pair of gears (3)
in the gearbox (101).
6. The lubrication system (200) as claimed in claim 5, wherein the at least one shifter fork
(7) is defined with at least one guideway (9) tangential to the passage defined on the at
17
least one shifter sleeve (4) to receive and guide the oil from the first channel (201) to
the second channel (202) through the at least one aperture (10).
7. The lubrication system (200) as claimed in claim 6, wherein the at least one guideway
5 (9) is defined with gradually decreasing diameter to supply pressurized flow of the oil
towards the at least one aperture (10).
8. The lubrication system (200) as claimed in claim 6, wherein the at least one aperture (10)
is defined at one end of the at least one guideway (9) of the at least one shifter fork (7)
10 to allow flow of the oil from the first channel (201) to the second channel (202).
9. The lubrication system (200) as claimed in claim 3, wherein the at least one oil duct (8)
and at least one rear casing (1’) define a third channel (203) that is configured to receive
the oil from the second channel (202) to lubricate the output section (14) of the gearbox
15 (101).
10. The lubrication system (200) as claimed in claim 3, wherein the at least one oil duct (8)
is positioned at a gradient relative to length of the casing (1).
20 11. The lubrication system (200) as claimed in claim 4, wherein a portion of at least one
rear casing (1’) defines a return channel (204) along length of the gearbox assembly
(100) for re-circulation of the oil from the output section (14) to the casing (1), and
wherein the at least one rear casing (1’) comprises a bushing (12) to house the output
shaft (5), and a propeller shaft and defined with a plurality of grooves (11) to allow
25 flow of the oil from the third channel (203) to the return channel (204).
12. The lubrication system (200) as claimed in claim 3, wherein the second channel (202)
is defined extending along length wise direction of the casing (1) of the gearbox
assembly (100).
30
13. The lubrication system (200) as claimed in claim 2, wherein the at least one pair of
gears (3) are positioned proximal to the output shaft (5) of the gearbox assembly (100)
and comprises:
a first gear positioned on the at least one gear shaft (2);
35 a second gear (3a) positioned on the output shaft (5), wherein diameter of the
first gear is less than diameter of the second gear (3a).
18
14. A gearbox assembly (100) for a vehicle, the assembly (100) comprising:
a casing (1) configured to accommodate at least one gear shaft (2), wherein the
at least one gear shaft (2) is configured to accommodate at least one pair of gears (3);
5 at least one rear casing (1’) defined on one end of the casing (1) configured to
accommodate an output shaft (5);
at least one shifter sleeve (4) slidably disposed on the at least one gear shaft (2);
at least one shifter fork (7) connected to a shifter shaft (6), the at least one shifter
fork (7) being configured to receive the at least one shifter sleeve (4); and
10 a lubrication system (200) fluidly connecting the at least one shifter sleeve (4),
the at least one pair of gears (3), and the at least one shifter fork (7), wherein the
lubrication system (200) comprising:
at least one oil duct (8) fluidly connected to the at least one shifter fork
(7), the at least one oil duct (8) being structured to extend between the at least one
15 shifter sleeve (4) and an output section (14) of a gearbox (101), the at least one
oil duct (8) being configured to receive oil from the at least one shifter fork (7)
and to direct the oil into the output section (14) of the gearbox (101).
15. The gearbox assembly (100) as claimed in claim 14, wherein the at least one shifter
20 fork (7) and the at least one shifter sleeve (4) define a first channel (201) configured to
guide the oil to the at least one shifter sleeve (4), from a casing (1) of the gearbox (101)
by the at least one pair of gears (3).
16. The gearbox assembly (100) as claimed in claim 15, wherein the at least one shifter
25 fork (7) and the at least one oil duct (8) define a second channel (202) along a portion
of the casing (1) to convey the oil.
17. The gearbox assembly (100) as claimed in claim 16, wherein the at least one oil duct
(8) and the at least one rear casing (1’) define a third channel (203) that is configured
30 to receive the oil from the second channel (202) to lubricate the output section (14).
18. The gearbox assembly (100) as claimed in claim 14, wherein a portion of the at least
one rear casing (1’) defines a return channel (204) along length of the gearbox assembly
(100) for re-circulation of the oil from the output section (14) to the casing (1), and
35 wherein the at least one rear casing (1’) comprises a bushing (12) to house the output
19
shaft (5) and a propeller shaft and defined with a plurality of grooves (11) to allow flow
of the oil from the third channel (203) to the return channel (204).
19. The gearbox assembly (100) as claimed in claim 16, wherein the at least one shifter
5 fork (7) is defined with at least one aperture (10) to receive the oil from the first channel
(201) and allow flow of the oil to the at least one oil duct (8) to define the second
channel (202).