FORM2
THE PATENTS ACT 1970
39 OF 1970
&
THE PATENT RULES 2003
COMPLETESPECIFICATION
(SEE SECTIONS 10 & RULE 13)
1. TITLEOF THE INVENTION
“AUTOMATIC GEAR ACTUATION MECHANISM IN ELECTRIC
VEHICLE”
2. APPLICANTS (S)
(a) Name: Varroc Engineering Limited
(b) Nationality: Indian
(c) Address: L-4, Industrial Area,
Waluj MIDC, Aurangabad-431136, Maharashtra, India
3. PREAMBLETOTHEDESCRIPTION
COMPLETESPECIFICATION
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION
The present disclosure in general relates to a gear actuation mechanism in an electric
vehicle, and more specifically, it relates to an automatic gear actuation mechanism in the
5 electric vehicles.
CROSS-REFERENCE TO RELATED APPLICATION
This invention takes priority from provisional application No. 202321032283 filed on
10 June 7, 2023; the entirety of which is incorporated herein as reference.
BACKGROUND OF THE INVENTION
The statements in this section merely provide background information related to the
15 present disclosure and may not constitute prior art.
Most two wheeler electric vehicles do not offer shifting of gear ratios, which can be seen
in conventional vehicles with manual transmission and therefore, the driver only have an
option to accelerate by pressing a throttle and applying brakes to stop the vehicle. This is
20 done since electric motor can deliver required torque for the full vehicle driving speed
range.
There exits technology which offer different mode of driving such as sports and eco mode
with fixed gear ratio transmission, however option of changing gear ratio is not provided.
25 Providing shiftable gear ratio for electric two wheeler necessitates need of a mechanism
to automatically shift the gear as this will eliminate the issues arising from selection of wrong gears and revving too much leading to poor traction motor performance and early battery drains.
30 Further, the electric vehicle’s performance like acceleration, gradeability, drivable range
per charge can be improved by providing two or more gear ratios. A first gear for

providing higher torque at lower speed and a second gear for providing lower torque at higher vehicle speed and so on with multiple pre-defined ranges using gear ratios.
Therefore, there exists a need in which performance of gear shifting in electric two
5 wheeler should not be dependent on driver and it should be optimized to shift it
automatically.
SUMMARY OF THE INVENTION
10 This summary is provided to introduce a selection of concepts in a simplified format, that
are further described in the detailed description of disclosure. This summary is neither intended to identify key or essential inventive concepts of the disclosure nor is it intended for determining the scope of the disclosure. In an embodiment of the present disclosure, a gear actuation mechanism in electric vehicles is disclosed.
15
The embodiments presented herein propose a mechanical mechanism, which can shift the gear ratio from a lower gear to a higher gear and vice-versa automatically based on the vehicle speed without any manual intervention.
20 In one embodiment, a gear actuation assembly configured to automatically shift gears in
an electric vehicle. The gear actuation assembly comprising a gear actuator shaft assembly, wherein the gear actuator shaft assembly and the gear actuator shaft assembly further comprising a centrifugal assembly, configured within a drum is disposed at one end of the gear actuator shaft assembly, capable of generating an axial force along the
25 axis of the gear actuator shaft assembly; and a compression assembly is disposed at other
end of the gear actuator shaft assembly, capable of generating an axial force along the axis of the gear actuator shaft assembly, opposite to the axial force generated by the centrifugal assembly.
30 In another embodiment, the gear actuator shaft assembly further comprises a shifting fork
spring loaded ball assembly configured between the centrifugal assembly and the compression assembly.

In another embodiment, the compression assembly is configured to actuate at lower vehicle speed to engage a first gear pair P1-G1 (303)-(402) and the centrifugal assembly is configured to actuate at higher vehicle speed to engage a second gear pair P2-G2.
5 In another embodiment, at the lower vehicle speed, by default the first gear pair P1-G1 is
engage as the compression assembly is configured to produce more axial force as
compared to opposing axial force produced by the centrifugal assembly, and wherein at
higher vehicle speed, the second gear pair P2-G2 is engaged as the centrifugal assembly
is configured to produce more axial force as compared to opposing axial force produced
10 by the compression assembly.
In another embodiment, the centrifugal assembly configured within the drum, comprising
a cage having plurality of radial slots to which plurality of fly weights are rested by a
circular compression garter spring and, wherein the fly weights are configured to slide
15 radially along the plurality of radial slots provided in the cage.
In another embodiment, at the lower speed, the plurality of fly weights will be having less
centrifugal force due to which a radial force produced by them will be less, resulting in
less axial force produced by the drum and at the higher speed, the plurality of fly weights
20 will be having more centrifugal force due to which the radial force produced by them will
be more, resulting in more axial force produced by the drum.
In another embodiment, the centrifugal assembly comprises the rotating drum which is
axially pushed against a thrust bearing which is resting against a non-rotating shifting
25 fork, preventing wearing out of contact face of rotating drum and non-rotating shifting
fork.
In another embodiment, the compression assembly comprises an axial actuator spring
which is resting on a shifter fork at one end and its other end is resting on a bearing holder
30 and configured in such a manner that the spring is having only one degree of freedom
with is axial movement and is prevented from winding up due to rotation of speed increaser gear S3 by use of thrust bearing.

In another embodiment, the gear actuator shaft assembly further comprises an actuator shaft having plurality of locating grooves, a spherical ball, a ball outer race, a spring and a spring tensioner screw which prevents unintentional disengagement of current gears.
5 In another embodiment, the drum internal geometry is conical or concave or parabolic
and the like which resolves the radial force of fly the weights into axial force.
To further clarify advantages and features of the present disclosure, a more elaborated
description of the disclosure will be rendered by reference to specific embodiments
10 thereof, which is illustrated in the appended drawings. It is appreciated that these
drawings depict only typical embodiments of the disclosure and are therefore not to be considered limiting of its scope. The disclosure will be described and explained with additional specificity and detail with the accompanying drawings.
15 BRIEF DESCRIPTION OF THE DRAWINGS
The features, nature, and advantages of the present disclosure will become more apparent
from the detailed description set forth below when taken in conjunction with the drawings
in which reference characters identify correspondingly throughout. Some embodiments
20 of system and/or methods in accordance with embodiments of the present subject matter
are now described, by way of example only, and with reference to the accompanying figures, in which:
Fig. 1A illustrates a block diagram of a proposed gear actuation mechanism when
25 engaged in first gear ratio, while Fig. 1B illustrates a cross-sectional view of the gear
actuation mechanism, in accordance with an embodiment of the present invention;
Fig. 2A illustrates a block diagram of a proposed gear actuation mechanism when
engaged in second gear ratio, while Fig. 2B illustrates a cross-sectional view of the gear
30 actuation mechanism, in accordance with an embodiment of the present invention;

Fig. 3 illustrates cross-sectional view of gearbox input shaft assembly, in accordance with an embodiment of the present invention;
Fig 4. illustrates a cross-sectional view of gearbox output shaft assembly in accordance
5 with an embodiment of the present invention;
Fig. 5A-5B illustrates a speed increaser gear train which takes power from gearbox input shaft assembly and drives gear actuator shaft assembly, in accordance with an embodiment of the present invention; 10
Fig. 6 illustrates an exploded view of the gear actuator shaft assembly, in accordance with an embodiment of the present invention;
Fig. 7A illustrates a design of fly weight assembly, while Fig. 7B illustrates exploded
15 view of the fly weight assembly, in accordance with an embodiment of the present
invention;
Fig. 8A illustrates a cross-sectional view of input shaft assembly and gear actuator shaft
assembly, while Fig. 8B illustrates isometric view of both shaft assemblies while gears
20 are engaged in first gear ratio, in accordance with an embodiment of the present invention;
Fig. 9A illustrates a cross-sectional view of input shaft assembly and gear actuator shaft
assembly, while Fig. 9B illustrates isometric view of both shaft assemblies while gears
are engaged in second gear ratio, in accordance with an embodiment of the present
25 invention; and
Fig. 10A- Fig. 10B illustrates a partial cross-sectional view of gear actuator shaft assembly to elaborate the forces involved when the gears are engaged in first and second gear respectively, in accordance with an embodiment of the present invention. 30
Further, skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and may not have been necessarily drawn to scale. For example, the flow charts

illustrate the method in terms of the most prominent steps involved to help to improve
understanding of aspects of the present disclosure. Furthermore, in terms of the
construction of the device, one or more components of the device may have been
represented in the drawings by conventional symbols, and the drawings may show only
5 those specific details that are pertinent to understanding the embodiments of the present
disclosure so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.
DETAILED DESCRIPTION
10
The terms “comprise”, “comprising”, “include(s)”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, system, or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup
15 or system or method. In other words, one or more elements in a system or apparatus
proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus.
In the following detailed description of the embodiments of the disclosure, reference is
20 made to the accompanying drawings that form a part hereof, and in which are shown by
way of illustration specific embodiments in which the disclosure may be practiced. These
embodiments are described in sufficient detail to enable those skilled in the art to practice
the disclosure, and it is to be understood that other embodiments may be utilized and that
changes may be made without departing from the scope of the present disclosure. The
25 following description is, therefore, not to be taken in a limiting sense.
Embodiments of the present disclosure will be described below in detail with reference
to the accompanying drawings and Table 1 describing the parts. In accordance with an
embodiment, the different conditions for gear shifting are first gear engaged (first
30 condition) and second gear engaged (second condition).

Fig. 1A illustrates a block diagram of a proposed gear actuation mechanism/assembly
when engaged in first gear ratio, while Fig. 1B illustrates a cross-sectional view of the
gear actuation mechanism/assembly. According to one embodiment, the automatic gear
actuation mechanism/assembly (100) for an electric vehicle majorly includes three shaft
5 assemblies, which are an input shaft assembly (300), an output shaft assembly (400) and
a gear actuator shaft assembly (600). Further, a motor (102) which can be a traction motor is operationally coupled to the input shaft assembly (300). A synchronizer assembly (302) which can be seen in Fig. 1 is further explained with respect to Fig. 3. The input shaft assembly (300) as shown in Fig. 3 consists of the synchronizer assembly (302) which is
10 splined on a input shaft (301), a pinion gear P1 (303) and a pinion gear P2 (304) which
are freely idling on a needle roller bearings on the input shaft (301). The speed increaser gear S1 (501) is keyed on the input shaft (301) using a key (306), distance pieces (307) (308) and two bearings (309) on which the input shaft assembly (300) is resting in the gear actuation assembly (100). The synchronizer assembly (302) gear shifting sleeve is
15 actuated by a shifting fork (608) (as shown in Fig. 6) of the gear actuator shaft assembly
(600). The shifting fork (608) working is explained in detail in the further description of the accompanying drawings.
An output shaft assembly (400) refer to Fig. 4 consists of two output gears which are a
20 gear G1 (402) and a gear G2 (403) which are positively connected to an output shaft (401)
by key or spline or press fit, distance pieces (405) (406) and two bearings (407) on which the output shaft (401) is resting in gearbox. The other end of the output shaft assembly (400) is coupled to the vehicle’s drive to transfer the torque generated by the traction motor (102). 25
According to an embodiment, fraction of power from the input shaft (301) is given to gear
actuator shaft assembly (600) by using a simple speed increaser gear train S1-S2-S3
(500), refer to Fig 5A-5B. According to an alternative embodiment, a compound gear
train may also be used based on speed requirement for the gear actuator shaft assembly
30 (600). A speed increaser gear S1 (501) is positively connected to the input shaft (301) by
a key (306) or by other suitable positive connection like spline and the like. A speed increaser gear S2 (502) is idling on a bearing (505) which is mounted on a pin (504). The

pin (504) is mounted on to a housing using a nut (507) and a locknut (508) arrangement or suitable mounting to clamp it in gearbox housing. To prevent oil seepage out of a gearbox O-ring a suitable sealant can be provided on the pin (504). A speed increaser gear S3 (503) is positively assembled on to the actuator shaft (601) using a key (602) or other 5 suitable positive locking mechanism like spline connection.
According to an embodiment, at lower motor (102) speeds, the synchronizer assembly (302) is pushed to left engaging to the first pinion gear P1 (303) by default by the gear actuator mechanism (600) working of which will be described later. Fig 1A illustrates the
10 power flow, when the motor (102) is running at lower speed. Power from the traction motor (102) is given to the input shaft (301), and then to the synchronizer (302) which then drives the output shaft (401) via first gear pair P1G1 (303) (402) giving first gear ratio igl . Fig 1B shows the cross-sectional view of the full gearbox assembly when the first gear is engaged.
15
At higher motor (102) speed, the synchronizer (302) is pushed to right engaging to the second pinion gear P2 (304) due to gear actuator mechanism (600) working of which will be described later. Fig 2A illustrates the power flow when the motor is running at higher speed. Power from the traction motor (102) is given to the input shaft (301), and then to
20 the synchronizer (302) which then drives output shaft (401) via the second gear pair P2G2 (304) (403) giving second gear ratio ig2. Fig 2B shows a cross-sectional view of the full gearbox assembly when the second gear is engaged.
Further, when the motor (102) speed drops below a threshold limit, the gear actuation 25 mechanism (600) pushes the synchronizer (302) to left, thus resulting in first gear ratio
igl. The threshold limit of speed at which the gear needs to be changed is determined
during the vehicle traction- speed design stage based on vehicle performance
requirements like top speed, weight, gradability, acceleration of the vehicle and
accordingly threshold limit will vary from vehicle to vehicle. 30
To understand the working of gear actuation mechanism (600), Fig 6. has to be read along
with Fig 7A-7B, Fig 8A-8B, Fig 9A-9B and with Table 1.

A cross-sectional view of the input shaft assembly (300) and gear actuator shaft assembly
(600) are shown in Fig 8A and Fig 9A, when the first gear pair P1-G1 (303)- (402) and
the second gear pair P2-G2 (304)-(403) are engaged respectively. Fig 8B and Fig 9B show
5 corresponding assembly of the input shaft assembly (300) and the gear actuator shaft
assembly (600).
As depicted in Fig. 6, the gear actuator shaft assembly (600) has mainly three sub-assemblies, which are a compression assembly (600A), a centrifugal assembly (600B)
10 and a shifting fork spring loaded ball assembly (600C). The compression assembly
(600A) generates an axial force in the direction of the pinion gear P1 (303), the centrifugal assembly (600B) generates an axial force in the direction of the pinion gear P2 (304), and the spring loaded ball assembly (600C) generates radial force to keep respective gears engaged.
15
An actuator shaft (601) is supported in housing on a bearing (603). Power to the actuator shaft (601) is given by the speed increaser gear S3 (503) which is positively connected using a key (602). The peed increaser gear S3 (503) has integral flange collar on which thrust bearing 2 (604) is resting. The other side of the thrust bearing 2 (604) is resting on
20 a thrust bearing holder (605). The shifting fork (608) and the thrust bearing holder (605)
are coupled together by slide fit spline so that linear movement is possible in between them. The shifting fork (608) is slide fit on to the actuator shaft (601) and its fork is coupled to a gear shifting sleeve of the synchronizer assembly (302). This locks all other degrees of freedom of shifting fork (608) except for linear movement along the axis of
25 the actuator shaft (601). This results in the thrust bearing holder (605) to have only one
degree of freedom of linear movement along the axis of the actuator shaft (601). Since speed increaser gear S3 (503) is rotary part and the thrust bearing holder (605) is non-rotary part, the thrust bearing 2 (604) is used to have relative rotary motion between them. The thrust bearing 2 (604) can be oil lubricated by keeping its enclosure open and using
30 oil from gearbox or as shown in Fig 8A can be greased in between the enveloping space
of the thrust bearing holder (605) and the speed increaser gear S3 (503). For refilling

purpose, a grease plug (606) is used. The gearbox can have suitable opening provision for accessing these plugs (606) when needed.
The actuator spring (607) is placed in between the shifting fork (608) and the thrust
5 bearing holder (605) and is rested on collar of respective parts. Thus, the actuator spring
(607) always pushes the shifting fork (608) to left along pinion gear P1 (303) direction by force ��. At lower motor (102) speeds, this force �� is dominant and keeps the shifting fork (608) engaged to left position giving first gear ratio ��1.
10 When in the first gear as shown in Fig 8A, Fig 10A-10B to prevent disengagement of the
shifting fork (608), a spring-loaded ball assembly is used on the shifting fork (608). The actuator shaft (601) has two revolve cuts made at two positions one at each position of the shifting fork (608) in gear engaged position in which a spherical ball (609) engages. A plurality of grooves (616A, 616B) in the actuator shaft (601) act as an inner race of
15 bearing. Enclosing the spherical ball (609) in top is a ball outer race (610) having semi
hemispherical recess, which acts as an outer race of bearing which can slide radially inside the radial groove provided on the shifting fork (608). A spring tensioner screw (612) is threaded in the shifting fork (608) and presses the spring (611) against the ball outer race (610). Thus, when the first gear is engaged, the actuator shaft (601) is continuously
20 rotating and the spherical ball (609) is continuously revolving about its own axis, while
the compression of the spring (611) gives a radial force on the spherical ball (609). This prevents automatic disengagement of the shifting fork (608). When the shifting fork (608) is pushed to right (which will be described later), the spherical ball (609) along with the ball outer race (610) will slide up against the spring (611) and when second gear is
25 engaged, the spherical ball (609) will fall in the second groove of the actuator shaft (601)
as shown in Fig 9A and Fig 10B.
On the other face of the shifting fork (608), a sleeve is given on which the thrust bearing
1 (613) rests. This bearing is given to take care of the relative motion between the shifting
30 fork (608) and a rotating drum (615). As explained earlier, the thrust bearing 1 (613) can
be oil lubricated by keeping the envelope open in the gearbox or can be grease filled in the mating parts envelope and a plug (606) is given to refill the grease. The enveloping

pockets for grease are made such that same grease can be used for the thrust bearing 1
(613) and the spring-loaded spherical ball (609).
As shown in figure 8A, the cage (701) is positively connected to the actuator shaft
5 (601) using a spline. Axial movement of the cage (701) is restricted by using two circlips
(614) on its both sides on the actuator shaft (601). Thus, fly weight assembly (700) and
actuator shaft (601) are rotating at same speed.
As shown in Fig 7A-7B, the cage (701) design has a resting face on which three fly
10 weights (702A, 702B, 702C) can rest. Along with that cage (701), three radial slots
(701A, 701B, & 701C) along which three fly weights (702A, 702B, 702C) can radially
slide. At low speed to keep these fly weights (702A, 702B, 702C) seated on cage (701)
resting face a garter spring (703) is used. These three parts i.e. the cage (701), the fly
weights (702A, 702B, 702C) and the garter spring (703) together form fly weight
15 assembly (700).
As shown in Fig 8A and Fig 9A, the fly weight assembly (700) which is positively splined
to the actuator shaft (601) and are axially locked using two circlips (614). The drum (615)
encloses this fly weight assembly (700) and is positively connected to the actuator shaft
20 (601) using slide fit spline. The drum (615) can slide axially on the actuator shaft (601),
however, its sliding length is restricted by using two circlips (614) on its either sides equivalent to gear shifting motion of the shifting fork (608). As explained earlier, the thrust bearing 1 (613) rests on extended part of this rotating drum (615).
25 As shown in Fig 8A and Fig 10A, at lower speed, the fly weights (702A, 702B, 702C)
will be seated on the cage (701) resting face due to the garter spring (703) force ���. Thus, the fly weight assembly (700) won’t be exerting any significant centrifugal force �� on to enveloping the drum (615). �� will be horizontal component of this centrifugal force �� magnitude of which will be dependent on inner geometry of the drum (615). The resulting
30 axial force �� to right will also be less on the drum (615). On the other hand, the actuator
spring (607) is generating axial force �� and pushes the shifting fork (608) to left. The movement of the shifting fork (608) to left is limited by left circlip (614) used for locating

the drum (615). Thus, engaging first gear pair P1G1 (303)- (402) and resulting in first gear ratio ��1. To avoid accidental disengagement of the first gear pair, the spring loaded ball assembly is used as already discussed.
5 As shown in Fig 9A and Fig 10B at higher speed, the fly weights (702A, 702B, 702C) will be sliding radially out due to centrifugal force �� generating significant axial force �� to right on the drum (615). The mechanism is designed in such a way that at particular rpm of motor the axial force �� is more than resisting axial force �� of the actuator spring (607). This results in movement of the drum (615) and the shifting fork (608) to right. 10 Thus, engaging the second gear pair P2G2 (304)-(403) and resulting in second gear ratio ��2. To avoid accidental disengagement of the second gear pair, the spring loaded ball assembly is used as already discussed.
Radial grooves are provided in enveloping the drum (615) to remove any oil that might 15 enter in it. The oil collected into extended enveloping area of the gearbox for the gear actuation mechanism is drained down to gearbox oil sum.
Fig 10A and Fig 10B show the forces involved on gear actuator shaft assembly (600) mechanism at low and at high rpm of motor. 20
a)
At lower rpm:
If the first gear P1G1 is engaged-
As illustrated in Fig 10A, the resisting spring force �� is more than resultant axial
force ��.
If second gear is already engaged and then motor rpm drops to lower value then:
As already known synchronizer needs axial force to shift from one gear to another.
Say 100 N force is needed at shifting fork (608) to move from second gear to first
30 gear then mechanism is designed in such a way that:
�� + 100 < ��

This results in movement of shifter fork (608) to shift to left and gives first gear ratio ��1 when motor rpm is below the threshold value for first gear ratio.
b) At higher rpm:
5 As illustrated in Fig 10B, the resisting spring force �� is less than resultant axial
force ��.
As already known synchronizer needs axial force to shift from one gear to another. Say 100 N force is needed at shifting fork (608) to move from first gear to second gear then mechanism is designed in such a way that: 10
��> �� + 100 This results in movement of shifter fork (608) to shift to right and gives second gear ratio ��2.
15 While specific language has been used to describe the present subject matter, any limitations arising on account thereto, are not intended. As would be apparent to a person in the art, various working modifications may be made to the method in order to implement the inventive concept as taught herein. The drawings and the foregoing description give examples of embodiments. Those skilled in the art will appreciate that
20 one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment.

Table 1
Reference Numeral Description
100 Gear actuation mechanism /assembly
102 Traction motor
600 Gear actuator shaft assembly
503 Speed increaser gear S3
601 Actuator shaft
602 Key
603 Bearing
604 Thrust bearing 2 Compression assembly 600A
605 Thrust bearing holder

606 Plug
607 Actuator spring

608 Shifting fork Shifting fork spring
loaded ball assembly
600C
609 Spherical ball

610 Ball outer race

611 Spring

612 Spring tensioner screw

613 Thrust bearing 1 Centrifugal assembly 600B
700 Fly weight assembly

614 Circlip

615 Drum

616A, 616b Grooves
300 Input shaft assembly
301 Input shaft
302 Synchronizer assembly
303 Pinion gear P1
304 Pinion gear P2
305 Needle roller bearing
501 Speed increaser gear S1
306 Key
307 Distance piece
308 Distance piece
309 Bearing
400 Output shaft assembly
401 Output shaft
402 Gear G1
403 Gear G2
404 Circlip
405 Distance piece
406 Distance piece
407 Bearing
500 Speed increaser gears
501 Speed increaser gear S1
502 Speed increaser gear S2
503 Speed increaser gear S3
504 Pin
505 Bearing
506 Distance piece
507 Nut
508 Locknut
700 Fly weight assembly
701 Cage

701A,
701B,
701C Plurality of radial slots
702A,
702B,
702C Fly weights
703 Garter spring

We Claim:
1. A gear actuation assembly (100) configured to automatically shift gears in an
electric vehicle comprising:
5 a gear actuator shaft assembly (600), wherein the gear actuator shaft
assembly (600) comprising:
a centrifugal assembly (600B), configured within a drum (615) is
disposed at one end of the gear actuator shaft assembly (600), capable of
generating an axial force along the axis of the gear actuator shaft assembly
10 (600); and
a compression assembly (600A) is disposed at other end of the gear actuator shaft assembly (600), capable of generating an axial force along the axis of the gear actuator shaft assembly (600), opposite to the axial force generated by the centrifugal assembly (600B).
15

20

2. The gear actuation assembly (100) as claimed in claim 1, wherein the gear
actuator shaft assembly (600) further comprises a shifting fork spring loaded ball
assembly (600C), configured between the centrifugal assembly (600B) and the
compression assembly (600A).
3. The gear actuation assembly (100) as claimed in claim 1, wherein the compression
assembly (600A) is configured to actuate at lower vehicle speed to engage a first
gear pair P1-G1 (303)-(402) and the centrifugal assembly (600B) is configured to
actuate at higher vehicle speed to engage a second gear pair P2-G2 (304)-(403).

25
4. The gear actuation assembly (100) as claimed in claim 3, wherein at the lower
vehicle speed, by default the first gear pair P1-G1 (303)-(402) is engage as the
compression assembly (600A) is configured to produce more axial force as
compared to opposing axial force produced by the centrifugal assembly (600B),
30 and wherein at higher vehicle speed, the second gear pair P2-G2 (304)-(403) is
engaged as the centrifugal assembly (600B) is configured to produce more axial

force as compared to opposing axial force produced by the compression assembly (600A).
5. The gear actuation assembly as claimed in claim 1, wherein the centrifugal
5 assembly (600B) configured within the drum (615), comprising a cage (701)
having plurality of radial slots (701A, 701B, 701C) to which plurality of fly
weights (702A, 702B, 702C) are rested by a circular compression garter spring
(703) and, wherein the fly weights (702A, 702B, 702C) are configured to slide
radially along the plurality of radial slots (701A, 701B, 701C) provided in the
10 cage (701).
6. The gear actuation assembly (100) as claimed in claim 5, wherein at the lower
speed, the plurality of fly weights (702A, 702B, 702C) will be having less
centrifugal force due to which a radial force produced by them will be less,
15 resulting in less axial force produced by the drum (615) and at the higher speed,
the plurality of fly weights (702A, 702B, 702C) will be having more centrifugal force due to which the radial force produced by them will be more, resulting in more axial force produced by the drum (615).
20 7. The gear actuation assembly (100) as claimed in claim 1, wherein the centrifugal
assembly (600B) comprises the rotating drum (615) which is axially pushed against a thrust bearing (613) which is resting against a non-rotating shifting fork (608), preventing wearing out of contact face of rotating drum (615) and non-rotating shifting fork (608).
25
8. The gear actuation assembly (100) as claimed in claim 1, wherein the compression
assembly (600A) comprises an axial actuator spring (607) which is resting on a
shifter fork (608) at one end and its other end is resting on a bearing holder (605)
and configured in such a manner that the spring (607) is having only one degree
30 of freedom with is axial movement and is prevented from winding up due to
rotation of speed increaser gear S3 (503) by use of thrust bearing (604).

9. The gear actuation assembly (100) as claimed in claim 1, wherein the gear actuator
shaft assembly (600) further comprises an actuator shaft (601) having plurality of
locating grooves (616A, 616B), a spherical ball (609), a ball outer race (610), a
spring (611) and a spring tensioner screw (612) which prevents unintentional
5 disengagement of current gears.
10. The gear actuation assembly (100) as claimed in claim 5, wherein the drum (615)
internal geometry is conical or concave or parabolic and the like which resolves
the radial force of fly the weights (702A, 702B, 702C) into axial force.