FORM 2
THE PATENTS ACT, 1970
[39 of 1970]
&
5 THE PATENTS RULES, 2003
10 COMPLETE SPECIFICATION
[See Section 10 and Rule 13]
15
TITLE: “A VARIABLE COMPRESSION RATIO ENGINE”
20 Name and Address of the Applicant: TATA MOTORS PASSENGER VEHICLES LIMITED, [Nationality: Indian] of Floor 3, 4, Plot-18, Nanavati Mahalaya, Mudhana Shetty Marg, BSE, Fort, Mumbai, Mumbai City, Maharashtra, 400 001.
Nationality: INDIAN
25
30

The following specification particularly describes the nature of the invention and the manner in which it is to be performed.
TECHNICAL FIELD
Present disclosure, in general, relates to the field of automobile engineering. Particularly, but 5 not exclusively, the present disclosure relates to an engine with variable compression ratio.
BACKGROUND
Engines are well-known prime movers in automobiles and power generation equipment.
10 Various types of engines are used for power generation such as two stroke and four stroke engines. In general, the engine includes a piston disposable within a bore, an air inlet port and an exhaust port, a connecting rod connectable to the piston, a crankshaft coupled to the connecting rod and further connected to a fly wheel. During operation, the piston disposed within the bore of the engines may reciprocate about a length of the bore for generating power
15 between two ends of the bore. Each reciprocating motion of the piston, as can be seen in Fig. 1 and Fig. 2, may be termed as ‘stroke’ of the piston, such that the piston reciprocates between a top-dead center (10A) and a bottom dead center (10B) of the engine. The total volume (30) covered by the piston during each stroke of travel of the piston may be termed as total volume (30). Further, the volume between the top dead center (10A) and an upper end of the bore may
20 be termed as clearance volume (20). During operation of the engine, the combustion of fuel may occur in the clearance volume (20). The ratio of the total volume of the bore by the clearance volume may be defined as compression ratio. Compression ratio is a significant parameter of an engine which is used to determine effective amount of power produced within the engine. Furthermore, the power generated by the engine is significantly dependent on the
25 total volume (30) covered by the engine.
Attempts at increasing the compression ratio of the engine include reducing the clearance volume (20) thereby increasing length of the compression stroke. However, such a configuration may result in pre-ignition of fuel mixture and knocking inside the engine 30 cylinder. This can cause severe damage to engine components. Also, if clearance volume is increased while increasing the length of Compression stroke, then excess amount of fuel mixture remains inside the cylinder at the end of the combustion stroke and results in incomplete combustion, which causes harmful emissions.

The present disclosure is directed to overcome one or more limitations stated above. The background section of the present disclosure should not be considered as a limitation of the present disclosure.
5 The drawbacks/difficulties/disadvantages/limitations of the conventional techniques explained in the background section are just for exemplary purpose and the disclosure would never limit its scope only such limitations. A person skilled in the art would understand that this disclosure and below mentioned description may also solve other problems or overcome the other drawbacks/disadvantages of the conventional arts which are not explicitly captured above.
10 SUMMARY OF THE DISCLOSURE
One or more shortcomings of the conventional design are overcome by a system as claimed and additional advantages are provided through the provision of such system as claimed in the present disclosure.
Additional features and advantages are realized through the design of the present disclosure. 15 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 disclosure, a variable compression ratio engine is disclosed. The engine includes of an engine block defined by a crankcase and a cylinder section extended from the crankcase. The cylinder section is defined with a bore. The engine includes
20 a crankshaft rotatable about a crank axis defined in the crankcase. Further, the engine includes a piston operatively connectable to the crankshaft and reciprocally disposable in the bore of the cylinder section of the engine block. Furthermore, the engine includes a connecting rod such that a first end of the connecting rod is connectable to the piston and a second end, opposite to the first end, is operatively connectable to the crankshaft. Additionally, the device includes an
25 actuating mechanism operatively connecting between a portion the connecting rod and the crankshaft. The actuating mechanism is operable between a first condition and a second condition. The actuating mechanism in the first condition is configured to regulate displacement of the connecting rod to regulate reciprocal movement of the piston to a first end position of the bore in the cylinder section. The actuating mechanism in the second condition
30 is configured to regulate displacement of the connecting rod to regulate reciprocal movement of the piston to a second end position of the bore in the cylinder section. Such regulated

movement of the piston from the first end position to the second end position is adapted to vary compression ratio from a first threshold to a second threshold.
In one embodiment of the disclosure, the actuating mechanism includes of a base disposable 5 relative to the engine block, a first sliding element slidably disposable on the base, a first connecting arm configured to guide the first sliding element relative to the engine block and a second connecting arm. The second connecting arm is configured to operatively connect to the first sliding element at one end and pivotably connect with an end of the connecting rod at the other end. The second connecting arm is configured to slide relative to the first connecting arm 10 based on displacement of the first sliding element, to selectively displace a pivotal point of the connecting rod, and regulate reciprocal movement of the piston between the first end position and the second end position of the bore in the cylinder section.
In one embodiment of the disclosure, the actuating mechanism includes of a second sliding
15 element, pivotably coupled to the second end of the connecting rod and slidably disposable
proximal to a first end of the second connecting arm. The second sliding element is configured
to pivot about the second end of the connecting rod and slide along the second connecting arm.
In one embodiment of the disclosure, the engine includes of a support rod pivotably coupled to 20 the crankshaft and configured to support the actuating mechanism.
In one embodiment of the disclosure, the actuating mechanism includes a third connecting arm
defined with a top end and a bottom end. The third connecting arm is positioned proximal to
the support rod and configured to support the actuating mechanism.
25
In one embodiment of the disclosure, the actuating mechanism includes of a third sliding
element pivotably coupled to the support rod and slidably disposed between the first end and
the second end of the second connecting arm. The third sliding element is and configured to
slide along the second connecting arm during the reciprocating movement of the piston.
30 Further, the actuating mechanism includes of a fourth sliding element pivotably coupled to the
support rod and slidably disposed between a top end and a bottom end of the third connecting
arm and configured to support the actuating mechanism.
In one embodiment of the disclosure, the actuating mechanism includes of an actuating means 35 positioned proximal to a first end of the first connecting arm and configured to actuate the actuating mechanism by at least one of manual operation of motor assisted operation.
4

In one embodiment of the disclosure, the base is parallel to at least a portion of the crank case relative to a surface of the engine block.
5 In one embodiment of the disclosure, the connecting rod is parallel to the support rod.
It is to be understood that the aspects and embodiments of the disclosure described above may
be used in combination with each other. Several of the aspects and embodiments may be
combined to form a further embodiment of the disclosure.
10
The foregoing summary is illustrative only and is not intended to be in any way limiting. In
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.
15
BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
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 20 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 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:
25 Fig. 1 is a representation of an construction of a conventional internal combustion (IC) engine.
Fig. 2 illustrates positions of piston in conventional IC engine with the piston proximal to a top dead center and a bottom dead center.
30 Fig. 3 illustrates a variable compression ratio engine disclosing various component of the variable compression ratio engine, in accordance with an embodiment of the present disclosure.
Fig. 4A-4B illustrates positions of the piston corresponding to a first condition of an actuating mechanism of the engine, in accordance with an embodiment of the present disclosure. 35

Fig. 5A-5B illustrates positions of the piston corresponding to a second condition of an actuating mechanism of the engine, in accordance with an embodiment of the present disclosure
5 The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
10 DETAILED DESCRIPTION
The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter
15 which form the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the conception and specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent processes do not depart from the scope of the disclosure as set forth in the appended claims.
20 The novel features which are believed to be characteristic of the disclosure, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition
25 of the limits of the present disclosure. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure.
30 The terms “comprises”, “comprising”, or any other variations thereof used in the specification, are intended to cover a non-exclusive inclusion, such that the system comprises a list of features/elements or steps does not include only those features/elements, but may include other features and elements not expressly listed or inherent to such setup or structure. In other words, one or more features/elements in a system proceeded by “comprises… a” does not, without
35 more constraints, preclude the existence of other elements or additional elements in the system

thereof. Also, the terms like “at least one” and “one or more” may be used interchangeably or in combination throughout the description.
Embodiments of the present disclosure relate to a variable compression ratio engine. The
5 engine comprises sliding elements and sliding arms operating relative to an engine block. An
actuating means consisting of the sliding elements and sliding arms may be operable between
a first condition and a second condition. The second condition of the actuating mechanism may
include increasing compression ratio of the engine by increasing the total length of travel of a
piston during each stroke of the engine without varying the clearance ratio.
10
Reference will now be made to the exemplary embodiments of the disclosure, as illustrated in
the accompanying drawings. Wherever possible, same numerals will be used to refer to the
same or like parts. Embodiments of the disclosure are described in the following paragraphs
with reference to Figs. 3 and Fig. 4, the same element or elements which have same functions
15 are indicated by the same reference signs.
Fig. 3 is representative of a variable compression ratio engine (200). The engine (200) may include an engine block (101) defining a crank case (152) and a cylinder section extending from the crankcase (152).The cylinder section may be defined with a bore (111) of predefined
20 diameter. Further, the engine (200) may include a piston (110) positioned within the bore (111) and configured to reciprocate about a length of the cylinder section of the engine block (101). Furthermore, the engine (200) may include a connecting rod (120) defined with a first end (120-A) and a second end (120-B). The first end of the connecting rod (120) may be connectable to the piston (110). Also, the engine (200) includes an actuating mechanism
25 operatively connectable to the piston (110) via the second end (120-B) of the connecting rod (120). The actuating mechanism is operable between a first condition [Best seen in Fig. 4A-4B] and a second condition [Best seen in Fig. 5A-5B]. In an embodiment, the piston (110) may be configured to reciprocate between a top portion of the bore namely, a top dead center (104) and a bottom portion of the bore (111). The total volume covered by the piston (110) during
30 the reciprocal movement of the piston (110) may be termed as total volume. Further, the volume between the top dead center (104) and an upper end of the bore (111) may be termed as clearance volume. During operation of the engine, the combustion of fuel may occur in the clearance volume. Ratio of the total volume of the bore (111) by the clearance volume may be defined as compression ratio. In an embodiment, actuating mechanism may be configured to
35 vary the compression ratio of the engine by increasing the travel of the piston.
7

Referring to Fig. 4A-4B, the first condition of the actuating mechanism corresponds to the reciprocal movement of the piston (110) from the top dead center (104) to a first end position (105a) of the bore (111). The second condition of the actuating mechanism corresponds to the 5 reciprocal movement of the piston (110) from the top dead center (104) to a second end position (105b) of the bore (111) [Best seen in Fig. 5A-5B]. Actuation of the actuating mechanism may regulate the movement of the piston (111) between a top dead center (104) and a first end position (105a) to a top dead center (104) and a second end position (105b). Such regulated movement of the piston may increase a length of travel of the bore (111) thereby increasing the
10 total volume available for fuel intake into the bore (111) of the engine (200). Actuation of the actuating mechanism may change travel of the piston (110) towards a bottom dead center without increasing travel of the piston (110) towards the top dead center (104). Increasing travel of the piston (110) increases the total volume covered by the piston (110) thereby. The regulated movement of the piston (110) from a first end position (105a) to the second end
15 position (105b) by the actuating mechanism advantageously allows for maintaining a clearance volume between the top dead center (104) and an upper end of the bore (111). Such increase of total volume by maintaining the same clearance volume may increase the compression ratio. Further, the actuating mechanism of engine (200) may be adapted to vary the compression ratio of the engine (200) from a first threshold to a second threshold. Additionally, pre-ignition of
20 fuel mixture, knocking inside the engine (200) and incomplete combustion of fuel is avoided by maintaining the same clearance volume.
Referring again to Fig. 3, the actuating mechanism of the engine (200) includes a base (180) disposable relative to the engine block (101) and positioned within the crankcase. The base
25 (180) may be structured to include at least a portion to be inclined at an angle and being parallel to at least a portion of the crank case (152) relative to a surface of the engine block (101). In an embodiment, the base (180) may be profiled to resemble trapezoidal shape, where the base (180) may be rigidly fixed within the crankcase. Further, the actuating mechanism of the engine (200) includes a first sliding element (160) which may be slidably disposed on the base (180).
30 The first sliding element (160) may be configured to slidably displace between a first end and a second end of the base (180) upon actuation of the actuating mechanism from the first condition to the second condition. Furthermore, the actuating mechanism of the engine (200) includes of a first connecting arm (161) positioned parallel to the first siding element (160) and configured to guide the first siding element (160) relative to the engine block (101) between a
8

first end and a second end of the base (180). In an embodiment, the first connecting arm (161) may be connectable to an actuation means (165) positioned outside the crankcase and operable manually or via a motor. In an embodiment, the first connecting arm (161) and the first siding element (160) may be connectable by means of but not limited to complementary worm gears 5 or lead screws. Additionally, the actuating means includes a second connecting arm (131) configured to operatively connect to the first sliding element (160) at a first end (132a) of the second connecting arm (131) and pivotably connecting with a second end (132b) of the second connecting arm (131). The second connecting arm (131) may be configured to slide relative to the first connecting arm (161) based on displacement of the first sliding element (160), to
10 selectively displace a pivotal point of the connecting rod (120). The displacement of the second connecting arm (131) relative to the first connecting arm (161) allows for reciprocal movement of the piston (110) between the top dead center (104) and the second end position (105b) of the bore (111) in the cylinder section. In an embodiment, the second connecting arm (131) may be defining a geometrical shape such as but not limited to a cylindrical structure. In an
15 embodiment, the second connecting arm (131) may be defining a hollow cylinder to allow higher torque transmission.
Referring again to Fig. 3, the actuating mechanism of the engine (200) includes of a second sliding element (130) pivotably coupled to the second end (120-B) of the connecting rod (120)
20 and slidably disposable proximal to the first end (132a) of the second connecting arm (131). The second sliding element (130) may be configured to pivot about the second end (120-B) of the connecting rod (120) and slide along the second connecting arm (131). Further, the crankcase includes a support rod (150) pivotably coupled to the crankshaft (151) and configured to support the actuating mechanism. Furthermore, the actuating mechanism
25 includes of a third sliding element (133) pivotably coupled to the support rod (150) and slidably disposed between the first end (132a) and the second end (132b) of the second connecting arm (131). The third sliding mechanism may be configured to slide along the second connecting arm (131). Furthermore, actuating mechanism consist of a third connecting arm (141) defined with a top end (142a) and a bottom end (142b). The third connecting arm (141) may be
30 positioned proximal to the support rod (150) and configured to support the actuating mechanism. In an embodiment, the third connecting arm (141) may be defining a geometrical shape such as but not limited to a cylindrical structure. In an embodiment, the third connecting arm may be defining a hollow cylinder to allow higher torque transmission. Additionally, the actuating mechanism includes of a fourth sliding element (140) pivotably coupled to the
9

support rod (150) and slidably disposed between the top end (142a) and the bottom end (142b) of a third connecting arm (141) and configured to support the actuating mechanism.
In an operational embodiment, when the actuation means (165) is enabled, the actuating 5 mechanism operates from a first condition to a second condition. When the actuating mechanism is operated between the first condition and the second condition, the first siding element (160) is slidably displaced from the first end of the base (180) to the second end of the base (180) and proximal to the cylinder section. Such displaced is enabled by the rotational movement of the first connecting arm (161) rotatable connected to the first siding element
10 (160). The movement of the first siding element (160) to the second end of the of the base (180) may enable reciprocal movement of the piston (110) between the top dead center (104) and the second end position (105b) of the bore (111). During operation of the piston (110) towards the second end position (105b), the third sliding element (133) displaces towards the second end (132b) of the second connecting arm (131). Further, the fourth sliding arm may be displaced
15 along the third connecting arm (141) towards the bottom end (142b) of the third connecting arm (141). The actuation of the actuating mechanism may rotate a crankshaft (151) connectable to the support rod (150) and operatively connectable to the piston (110). The rotation of the crankshaft (151) is connectable to a transmission for transmitting power from an engine (200). The displacement of the piston (110) from the first end position (105a) to the second end
20 position (105b) may contribute to increase in the total volume for compression of fuel, thereby increasing power output during a power stroke of the engine (200).
EQUIVALENTS
25 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 may be expressly set forth herein for sake of clarity.
30 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 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
35 within the art that if a specific number of an introduced claim recitation is intended, such an
10

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 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 5 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 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
10 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, or two or more recitations). Furthermore, in those instances where a convention analogous to
15 “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, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is
20 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 those within the art that virtually any disjunctive word and/or phrase presenting two or more
25 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.”
30 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.

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.
i

Referral Numeral:
Referral Numeral Description
100 Engine (Prior art)
10A Top dead center
10B Bottom dead center
20 Clearance volume
30 Total Volume
101 Engine block
200 Engine
104 Top dead center
105a First end position
105b Second end position
110 Piston
111 Bore
120 Connecting rod
130 Second sliding element
131 Second connecting arm
132a First end
132b Second end
133 Third sliding element
140 Fourth sliding element
141 Third connecting arm
142a Top end
142b Bottom end
150 Support rod
151 Crankshaft
152 Crank case
160 First sliding element
161 First connecting arm
161a First position
161b Second position
165 Actuation means
180 Base
1 3

We Claim:
1. A variable compression ratio engine (200), the engine (200) comprising:
an engine block (101) defined by a crankcase (152) and a cylinder section
5 extended from the crankcase, the cylinder section define with a bore (111);
a crankshaft (151) rotatable about a crank axis defined in the crankcase (170); a piston (110) operatively connectable to the crankshaft (151) and reciprocally disposable in the bore (111) of the cylinder section of the engine block (101),
a connecting rod (120), a first end (120-A) of the connecting rod being
10 connectable to the piston (110), and a second end (120-B) end, opposite to the first end
(120-A), being operatively connectable to the crankshaft (151);
an actuating mechanism operatively connecting between a portion the
connecting rod (120) and the crankshaft (151), the actuating mechanism operable
between a first condition and a second condition,
15 wherein the actuating mechanism, in the first condition, being configured to
regulate displacement of the connecting rod (120) to regulate reciprocal movement of
the piston (110) to a first end position (105a) of the bore (111) in the cylinder section,
and the actuating mechanism, in the second condition, being configured to regulate
displacement of the connecting rod (120) to regulate reciprocal movement of the piston
20 (110) to a second end position (105b) of the bore (111) in the cylinder section, wherein
such regulated movement of the piston (110) from the first end position (105a) to the second end position (105b), being adapted to vary compression ratio from a first threshold to a second threshold.
25 2. The engine (200) as claimed in claim 1, wherein the actuating mechanism comprising:
a base (180) disposable relative to the engine block (101), a first sliding element (160), slidably disposable on the base (180); a first connecting arm (161) configured to guide the first sliding element (160)
relative to the engine block (180); and
30 a second connecting arm (131), configured to operatively connect to the first
sliding element (160) at one end, and pivotably connect with an end of the connecting
rod (120) at the other end,
wherein the second connecting arm (131) configured to slide relative to the first
connecting arm (161) based on displacement of the first sliding element (160), to
14

selectively displace a pivotal point of the connecting rod (120), and regulate reciprocal movement of the piston (110) between the first end position (105a) and the second end position (105b) of the bore (111) in the cylinder section.
5 3. The engine (200) as claimed in claim 1, wherein the actuating mechanism comprises a
second sliding element (130), pivotably coupled to the second end (120-B) of the
connecting rod (120) and slidably disposable proximal to a first end (132a) of the
second connecting arm (131), and wherein the second sliding element (103) configured
to pivot about the second end (120-B) of the connecting rod (120) and slide along the
10 second connecting arm (131).
4. The engine (200) as claimed in claim 1 comprises a support rod (150) pivotably coupled to the crankshaft (151) and configured to support the actuating mechanism.
15 5. The engine (200) as claimed in claim 1 comprises a third connecting arm (141) defined
with a top end (142a) and a bottom end (142b), wherein the third connecting arm (141) is positioned proximal to the support rod (150) and configured to support the actuating mechanism.
20 6. The engine (200) as claimed in claim 1, wherein the sliding mechanism comprises:
a third sliding element (133) pivotably coupled to the support rod (150) and
slidably disposed between the first end (132a) and a second end (132b) of the second
connecting arm (131) and configured to slide along the second connecting arm (131);
a fourth sliding element (140) pivotably coupled to the support rod (150) and
25 slidably disposed between the top end (142a) and the bottom end (142b) of the third
connecting arm (141) and configured to support the actuating mechanism.
7. The engine (200) as claimed in claim 1 comprises an actuating means positioned
proximal to a first end (161a) of the first connecting arm (161) and configured to
30 actuate the actuating mechanism by at least one of manual operation or motor assisted
operation.
8. The engine (200) as claimed in claim 1, wherein the base (180) is at an angle with
respect to the crankcase and configured to adaptably slide the first sliding element
35 (160) over a surface of the base (180).

9. The engine (200) as claimed in claim 1, wherein at least one surface of the base (180) is parallel to the first connecting arm (161) for providing easy sliding movement.
10. A vehicle comprising a variable compression ratio engine (200) as claimed in claim 1.