Description:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)
A LIQUID COOLED INTERNAL COMBUSTION ENGINE
APPLICANT:
TVS MOTOR COMPANY LIMITED, an Indian Company at: “Chaitanya”, No. 12, Khader Nawaz Khan Road, Nungambakkam, Chennai – 600006
The following specification fully and particularly describes the invention and the manner in which it is to be performed.
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TECHNICAL FIELD
[0001] The present subject matter relates generally to a liquid cooled internal combustion engine, and particularly relates to a coolant pump that is mechanically coupled to a crankshaft of the internal combustion engine.
BACKGROUND
[0002] Generally, a vehicle comprises of a frame assembly extending rearwardly 5 from a head tube. The steering column passes through the head tube of the frame assembly. The frame assembly acts as a skeleton and a structural member for the vehicle that supports the vehicle loads. At least one front wheel is connected to a front portion of the frame assembly through one or more front suspension(s). The head tube is generally configured to accommodate the steering assembly and the 10 handlebar. The frame assembly extends towards a rear portion of the vehicle. At least one rear wheel is connected to a frame assembly through one or more rear suspension(s). The frame assembly comprises of an engine assembly coupled to it. The engine assembly is functionally connected to the rear wheel, which provides forward motion to the vehicle. The engine assembly comprises a cylinder head 15 mounted to a cylinder block. The cylinder head is mounted to a crankcase. The clutch assembly is enclosed by a clutch cover that is mounted to the crankcase. Similarly, the magneto is enclosed by a magneto cover that is mounted to the crankcase. The crankcase rotatably supports a plurality of engine components including the crankshaft. The engine assembly has a number of fins disposed on a 20 outer surface of the engine that is exposed to the atmosphere for cooling of the engine.
[0003] For engines of larger capacity, cooling the engine is a challenge and therefore, a liquid is provided in a jacket surrounding the engine for cooling the engine. A coolant pump is provided to pump the coolant to surround the engine. 25 The liquid being pumped cools the engine and absorbs the heat. The heated-up liquid then moves to the radiator and collects in a sump at the bottom of the
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crankcase. Heating up of the engine causes a reduction in engine performance and possible failure of the engine if not cooled effectively.
[0004] The liquid cooled engine assembly includes a clutch assembly and a magneto or an integrated starter generator mounted onto the crankcase. The crankcase may be an assembly of a crankcase-LH and a crankcase-RH. 5
[0005] Typically, in conventional vehicles, the coolant pump is provided on the same side of the liquid cooled internal combustion engine as the clutch and transmission assembly and mounted within the same portion of crankcase. Hence for servicing the clutch assembly, one must drain the coolant first, remove the coolant pump and then service the clutch which makes it difficult to service the 10 clutch. This leads to increased service time for conventional vehicles having the clutch mounted on the same portion of the crankcase. To reduce the service time for the clutch assembly and to better accommodate the coolant pump, the clutch assembly and the coolant pump are mounted onto different sides of the crankcase. Furthermore, the coupling is made of an elastic material such as rubber, synthetic 15 rubber, that loses its grip over time. Over continued usage, the coupling may lose the elastic properties leading to loosening of the grip which in turn leads to reduced power transmission leading to failure.
[0006] Therefore, the coolant pump is mounted to one side of the cylinder block of the liquid cooled internal combustion engine and the clutch assembly is mounted 20 on another side of the cylinder block. Thus, either the camshaft or the crankshaft is used to directly drive the coolant pump.
[0007] Therefore, it is a need in the art to have a solution that enables an effective and durable mechanical coupling between the coolant pump and the crankshaft of the liquid cooled internal combustion engine. 25
[0008] Moreover, in the existing state of the art, the coolant pump is directly coupled to the crankshaft through a coupler. The coupler needs replacement as it wears off over time. This increase serviceability costs. The coupler might also affect the transmission as it may loosen after a certain period of operation. This will again increase the frequency of service and adversely impact the performance 30 of the liquid cooled internal combustion engine. Therefore, to eliminate the
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problems of frequent service and loss of transmission on failure of the pump, there is a requirement for an effective and durable mechanical coupling of the coolant pump to the crankshaft of the liquid cooled engine.
SUMMARY 5
[0009] Aspects of the present invention pertain to a liquid cooled internal combustion engine (hereinafter also referred to as engine) for a vehicle. The liquid cooled internal combustion engine comprises a crankcase, a crankshaft disposed within the crankcase of the vehicle. A magneto is disposed on the crankshaft of the vehicle. A cover magneto covers the magneto. A coolant pump mounted on the cover magneto with the coolant pump is mechanically connected to the crankshaft through a gear assembly and is operative for cooling the liquid cooled internal combustion engine. The coolant pump is driven by rotary motion of the crankshaft. The gear assembly is composed of a first gear, a second gear and a third gear. The second gear is introduced to have a same direction of rotation of the coolant pump and the crankshaft. The first gear and the third gear are mechanically coupled to have same direction of rotary motion.
[00010] In an embodiment, the first gear comprises a keyway with the keyway adapted to lock with a pin inserted into a hole disposed on the crankshaft. The pin inserted into the hole locks the first gear to restrict translational motion of the first gear and ensures that the first gear follows a rotary motion of the crank shaft.
[00011] In an embodiment, the first gear further comprises a nut. The nut is adapted to interface with a flange of the crankshaft. The interface of the nut with the flange restricts axial motion of the first gear.
[00012] In an embodiment, the second gear is mounted on a first shaft and is mechanically connected to the first gear to transfer rotary motion of the first gear to the second gear.
[00013] In an embodiment, the third gear is mounted on a second shaft, the second shaft extending axially into the coolant pump. The third gear is mechanically coupled with the second gear to transfer rotary motion of the second gear to the
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third gear. A first end of the second shaft is configured to have a predetermined shape. In an embodiment, the predetermined shape is D shaped.
[00014] In an embodiment, the third gear is configured to have a slot, the slot is configured to have a profile corresponding to the predetermined shape of the first end of the second shaft. The slot can be an integrated D slot.
[00015] In an embodiment, the first end of the second shaft can be D shaped and can be configured to mate with the integrated D slot of the third gear.
[00016] In an embodiment, the cover magneto can be disposed on a right side of the internal combustion engine when viewed from a rear of the internal combustion engine, and the coolant pump can be assembled on an outer surface of the cover magneto.
[00017] In an embodiment, the coolant pump is inclined at an angle of up to 30 degrees relative to an axis of rotation of the crankshaft.
[00018] In an embodiment, the gear assembly comprises an outer casing subtending a cavity covering the first gear, the second gear and the third gear, the cavity is filled with a transmission fluid.
BRIEF DESCRIPTION OF THE DRAWINGS
[00019] The detailed description of the present subject matter is described with reference to the accompanying figures. Same numbers are used throughout the drawings to reference like features and components.
[00020] Fig. 1 illustrates a perspective view of an exemplary liquid cooled internal 5 combustion engine 100, in accordance with an embodiment of the present subject matter.
[00021] Fig. 2 depicts a cross-sectional view of a coolant pump 106 of the liquid cooled internal combustion engine 100 in accordance with an embodiment of the present invention. 10
[00022] Fig. 3 illustrates an exploded view of the gear assembly for mechanically coupling the coolant pump 106 to the crankshaft 108 in accordance with an embodiment of the present invention.
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[00023] Fig. 4 illustrates the coolant pump 106 mounted on a magneto cover (102) with a section A-A passing through a third gear 206 mounted on a second shaft (310) to drive the coolant pump 106.
[00024] Fig. 5 illustrates a sectional view of the coolant pump 106 along the axis A-A in accordance with an embodiment of the present invention. 5
DETAILED DESCRIPTION
[00025] It is an object of the present invention to provide an effective mechanical coupling between the coolant pump and the crankshaft of the liquid cooled internal combustion engine.
[00026] It is an object of the present invention to provide a coolant pump 10 operatively coupled to a liquid cooled internal combustion engine.
[00027] It is still another object of the present invention to provide a mechanical coupling between the crankshaft and the coolant pump which aids in prolonging life of said coolant pump.
[00028] It is yet another object of the present invention to eliminate the possibility 15 of failure due to usage of the conventional coupling assembly.
[00029] It is yet another object of the present invention to address the one or more failure mode of the existing state of the art, the coupling assembly.
[00030] With the above and other objects in view, the present invention provides a coolant pump operatively coupled to a crankshaft of a liquid cooled internal 20 combustion engine.
[00031] Exemplary embodiments are described with reference to the accompanying drawings. Wherever convenient, the same reference numbers are used throughout the drawings to refer to the same or like parts. While examples and features of disclosed principles are described herein, modifications, 25 adaptations, and other implementations are possible without departing from the spirit and scope of the disclosed embodiments. It is intended that the following detailed description be considered as exemplary only, with the true scope and spirit is indicated by the following claims.
[00032] The embodiments of the present invention will now be described in detail 30 with reference to an internal combustion engine along with the accompanying
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drawings. However, the present invention is not limited to the present embodiments. The present subject matter is further described with reference to accompanying figures. It should be noted that the description and figures merely illustrate principles of the present subject matter. Various arrangements may be devised that, although not explicitly described or shown herein, encompass the 5 principles of the present subject matter. Moreover, all statements herein reciting principles, aspects, and examples of the present subject matter, as well as specific examples thereof, are intended to encompass equivalents thereof.
[00033] Fig. 1 illustrates a perspective view of an exemplary liquid cooled internal combustion engine 100, in accordance with an embodiment of the present subject 10 matter. A general description of the liquid cooled internal combustion engine 100 in accordance with an embodiment of the present invention is made with reference to Fig.1.
[00034] The liquid cooled internal combustion engine 100, hereinafter 'engine' may be a single cylinder engine that includes a cylinder block 104. A cylinder head (not shown) is mounted on the cylinder block 104. In the present embodiment, the cylinder head is detachably attached to the cylinder block 104. A crankshaft 108 (shown in Fig. 2) which is piston driven serves as an output shaft of the liquid cooled internal combustion engine 100 and has a driving sprocket or a pulley (not shown) fixedly mounted thereto at one end thereof. The crankshaft 108 is disposed within a crankcase 110. Reciprocating motion of the piston disposed inside the cylinder block 104 is converted into rotary motion by the crankshaft 108. The crankshaft 108 is subject to a continuous change in angular velocity as the torque imparted to the crankshaft 108 during one complete cycle of operation of the engine 100 keeps fluctuating.
[00035] The engine (100) comprises a crankcase 110, a crankshaft 108 disposed within the crankcase 110 of the vehicle. The crankcase 110 may be a single part or two individual parts, the crankcase-LH and crankcase-RH that may be removably attached to form the crankcase (110). A magneto (not shown) is disposed on the crankshaft 108 of the vehicle and can be mounted on either side of the crankcase 110 (crankcase-RH or crankcase-LH). In this particular embodiment, the magneto
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is disposed on the crankcase-RH. A cover magneto 102 covers the magneto. A coolant pump 106 mounted on the cover magneto 102 is mechanically connected to the crankshaft 108 through a gear assembly (not shown) and is operative for cooling the engine 100. The coolant pump 106 is driven by rotary motion of the crankshaft 108. The gear assembly is composed of a first gear 202, a second gear 204 and a third gear 206 (Ref Fig. 2). The second gear 204 is introduced to have a same direction of rotation of the coolant pump 106 and the crankshaft 108. The first gear 202 and the third gear 206 are mechanically coupled to have the same direction of rotary motion through the second gear 204. The first gear 202 has a direction of rotation opposite to the direction of rotation of the crankshaft 108. The first gear 202 operatively meshes with the second gear 204. The second gear 204 has a direction of rotation opposite to the direction of rotation of the first gear 202. The third gear 206 meshes with the second gear 204 and rotates in a direction opposite to the direction of rotation of the second gear 204. The first gear 202 and the third gear 206 have the same direction of rotation.
[00036] Fig. 2 depicts a cross-sectional view of a coolant pump 106 of the liquid cooled internal combustion engine 100 in accordance with an embodiment of the present invention illustrating the interfacing between the first gear 202, the second gear 204 and the third gear 206. The direction of rotation of the first gear 202 and the third gear 206 is uniform. For instance, clock-wise rotation of the first gear 202 5 leads to a clock-wise rotation in the third gear 206 and second gear 204 will rotate in an antilock wise direction. The direction of rotation of the crankshaft 108 corresponds to the direction of rotation of the coolant pump 106.
[00037] Fig. 3, that illustrates an exploded view of the gear assembly to drive the coolant pump 106 that is mounted to the crankshaft 108 in accordance with an 10 embodiment of the present invention. In an embodiment, the first gear 202 comprises a keyway 314, the keyway 314 is adapted to lock with at least one pin 308 inserted into a hole (not shown) disposed on the crankshaft 108. The at least one pin 308 inserted into the hole locks the first gear 202 to restrict translational motion of the first gear 202 and ensures that the first gear 202 follows a rotary 15 motion of the crankshaft 108.
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[00038] The crankshaft 108 extends from a flywheel 312 to engage with the first gear 202. The flywheel 312 conserves the energy received from the crankshaft and transmits it through the clutch assembly to one or more wheels. The first gear 202 follows the rotary motion of crankshaft 108 and rotates in a direction opposite to the direction of rotation of the flywheel 312 and the crankshaft 108.
[00039] In an embodiment, the first gear 202 further comprises an interfacing member 316. The interfacing member 316 is adapted to interface with a flange (not shown) of the crankshaft 108. The interfacing member 316 can be a nut. The interface of the nut 316 with the flange restricts axial motion of the first gear 202.
[00040] The second gear 204 is mounted on a first shaft 304 and is mechanically connected to the first gear 202 to transfer rotary motion of the first gear 202 to the second gear 204. The second gear 204 rotates in a direction opposite to the direction of rotation of the first gear 202.
[00041] In an embodiment, the third gear 206 is mounted on a second shaft 310, the second shaft 310 extending axially into the coolant pump 106. The third gear 206 is mechanically coupled with the second gear 204 to transfer rotary motion of the second gear 204 to the third gear 206. A first end of the second shaft 310 is configured to have a predetermined shape. In an embodiment, the predetermined shape is D shaped.
[00042] In an embodiment, the third gear 206 is configured to have a slot 306, the slot 306 is configured to have a profile corresponding to the predetermined shape of the first end of the second shaft 310. The slot 306 can be an integrated D slot. The integrated D slot receives the second shaft 310 that is a drive shaft of the coolant pump 106.
[00043] In an embodiment, the cover magneto 102 can be disposed on a right side of the engine 100 when viewed from a rear of the engine 100, and the coolant pump 106 can be assembled on an outer surface of the cover magneto 102.
[00044] Figs. 4 and 5 shall be explained together for the sake of brevity. Fig. 4 illustrates the coolant pump 106 mounted on a magneto cover (102) with a section A-A passing through the third gear 206 mounted on a second shaft 310 to drive the coolant pump 106. Fig. 5 illustrates a sectional view of the coolant pump 106
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along the axis A-A passing through the third gear 206 and as shown in Figure 4 in accordance with an embodiment of the present invention.
[00045] The flywheel 312 rotates and the crankshaft 108 follows the rotation of the flywheel 312. The first gear 202 is mounted onto the crankshaft 108. The third gear 206 receives the rotary motion from the first gear 202 through the second gear 5 204.
[00046] In an embodiment, the coolant pump 106 is inclined in an predetermined angle range. The predetermined angle may be _ up to 30 degrees relative to an axis of rotation of the crankshaft 108.
[00047] In an embodiment, the gear assembly is housed within an outer casing subtended by the coolant pump. The cavity covers the first gear 202, the second gear 204_and the third gear 204and, the cavity is filled with a transmission fluid. The gears are lubricated by splash lubrication. The coolant pump 106 is used to circulate a coolant through the engine 100 in order to remove excess heat therefrom. The coolant supplied by the coolant pump 106 aids in maintaining optimum operating temperature of the engine 100. In an embodiment one or more sensors may be provided to determine the temperature and pressure of the engine 100, which together with the coolant pump 106 and a radiator (not shown) maintains the optimum operating temperature of the engine 100. The one or more sensors may be a thermostat and a pressure sensor.. When the coolant gets heated to a threshold temperature and the engine 100 has attained the optimum operating temperature, the thermostat may direct flow of the coolant to the radiator. Thereafter, the radiator after cooling the coolant directs the coolant to the engine 100 through an inlet (not shown) of the coolant pump 106. However, in a condition when the engine 100 has not attained its optimum operating temperature, the thermostat may be adapted to bypass the flow of the coolant directly to the coolant pump 106 through a bypass hose (not shown) and back to the engine 100 and the same is continued till the engine 100 attains the optimum operating temperature.
[00048] As is evident, the gear assembly provide an effective mechanical coupling 10 between the coolant pump 106 and the crankshaft 108 of the liquid cooled internal combustion engine 100. The mechanical coupling between the crankshaft 108 and
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the coolant pump 106 which aids in prolonging life of the coolant pump 106. In an embodiment, the operational life of the power transfer element, the gear assembly for mounting the coolant pump 106 onto the crankshaft 110 is increased thereby reducing the frequency of routine servicing of the vehicle. In one non-limiting implementation, the frequency of routine servicing is reduced by at least 2 times. 5 The operational life of the gear assembly rotating the cooling pump 106 is increased by at least 2 times the existing state of the art.
[00049] Furthermore, the liquid cooled internal combustion engine 100 as per the disclosed embodiment eliminates the possibility of failure in the form of loss of grip that is observed and is due to usage of the conventional coupling assembly 10 made of an elastic material.
[00050] As it is apparent from the above teaching, by providing a gear assembly as per the principle of the present invention and its various embodiments, for establishing a mechanical coupling between the coolant pump 106 to the crankshaft 108, the problem of having to regularly replace the conventionally used coupling is eliminated.
[00051] In view of the above, the claimed limitations as discussed above are not routine, conventional, or well understood in the art, as the claimed limitations enable the above solutions to the existing problems in conventional technologies.
[00052] The terms “an embodiment”, “embodiment”, “embodiments”, “the embodiment”, “the embodiments”, “one or more embodiments”, “some embodiments”, and “one embodiment” mean “one or more (but not all) embodiments of the invention(s)” unless expressly specified otherwise. The terms 15 “including”, “comprising”, “having” and variations thereof mean “including but not limited to”, unless expressly specified otherwise. The terms “a”, “an” and “the” mean “one or more”, unless expressly specified otherwise.
[00053] Finally, the language used in the specification has been principally selected for readability and instructional purposes, and it may not have been 20 selected to delineate or circumscribe the inventive subject matter and is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based here on. Accordingly,
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the embodiments of the present invention are intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.
[00054] 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 5 not intended to be limiting, with the true scope and spirit indicated by the following claims.
[00055] A person with ordinary skills in the art will appreciate that the systems, modules, and sub-modules have been illustrated and explained to serve as examples and should not be considered limiting in any manner. It will be further 10 appreciated that the variants of the above disclosed system elements, modules, and other features and functions, or alternatives thereof, may be combined to create other different systems or applications.
[00056] While the present disclosure has been described with reference to certain embodiments of a liquid cooled internal combustion engine, it will be understood 15 by those skilled in the art that various changes may be made, and equivalents may be substituted without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from its scope. Therefore, it is intended that the present disclosure not be limited to the particular 20 embodiment disclosed, but that the present disclosure will include all embodiments falling within the scope of the appended claims. , Claims:We claim:
1. A liquid cooled internal combustion engine (100) for a vehicle, the liquid cooled internal combustion engine (100) comprising:
a crankcase (110);
a crankshaft (108) disposed within the crankcase (110) of the vehicle;
a magneto disposed on the crankshaft (108) of the vehicle;
a cover magneto (102) covering the magneto disposed on the crankcase (110) of the vehicle; and
a coolant pump (106) mounted on the cover magneto (102),
wherein
wherein the coolant pump (100) being mechanically connected to the crankshaft (108) through a gear assembly and, wherein the coolant pump (106) being driven by a rotary motion of the crankshaft (108).
2. The liquid cooled internal combustion engine (100) as claimed in claim 1, wherein the gear assembly being comprised of at least a first gear (202), a second gear (204) and a third gear (206).
3. The liquid cooled internal combustion engine (100) as claimed in claim 2, wherein the first gear (202) comprising a keyway (314), the keyway (314) being adapted to lock with at least one pin (308) inserted into a hole disposed on the crankshaft (108) to lock the first gear (202) in position to follow a rotary motion of the crankshaft (108).
4. The liquid cooled internal combustion engine (100) as claimed in claim 2, wherein the first gear (202) comprising an interfacing member (316), the interfacing member (316) being adapted to interface with a flange of the crankshaft (110) wherein, the interface of the interfacing member (316) with the flange restricts axial motion of the first gear (202).
5. The liquid cooled internal combustion engine (100) as claimed in claim 2, wherein the second gear (204) being mounted on a first shaft (304) and
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being mechanically connected to the first gear (202) to transfer rotary motion of the first gear (202) to the second gear (204).
6. The liquid cooled internal combustion engine (100) as claimed in claim 2, wherein the third gear (206) being mounted on a second shaft (310), the second shaft (310) extending axially into the coolant pump (106), the third gear (206) being mechanically coupled with the second gear (204) to transfer rotary motion of the second gear (204) to the third gear (206).
7. The liquid cooled internal combustion engine (100) as claimed in claim 6, wherein a first end of the second shaft (106) being configured to have a predetermined shape, the predetermined shape being D shaped.
8. The liquid cooled internal combustion engine (100) as claimed in claim 2, wherein the third gear (206) being configured to have a slot (306), the slot (306) being configured to have a profile corresponding to the predetermined shape of the first end of the second shaft (106).
9. The liquid cooled internal combustion engine (100) as claimed in claim 9, wherein the slot (306) being an integrated D slot.
10. The liquid cooled internal combustion engine (100) as claimed in claim 6, wherein the first end of the second shaft (310) being D shaped and configured to mate with the integrated D slot of the third gear (206).
11. The liquid cooled internal combustion engine (100) as claimed in claim 1, wherein the cover magneto (102) being disposed on a right side of the liquid cooled internal combustion engine (100) when viewed from a rear of the liquid cooled internal combustion engine (100), and the coolant pump (106) being assembled on an outer surface of the cover magneto (102).
12. The liquid cooled internal combustion engine (100) as claimed in claim 1, wherein the coolant pump (106) being inclined at an angle of up to 30 degrees relative to an axis of rotation of the crankshaft (106).
13. The liquid cooled internal combustion engine (100) as claimed in claim 2, wherein the gear assembly being housed within a cavity subtended by the coolant pump (106) and the crankshaft (108), the cavity being adapted to
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house the first gear (202), the second gear (204) and the third gear (206), the cavity being filled with a transmission fluid.
14.The liquid cooled internal combustion engine (100) as claimed in claim 2,wherein the second gear (204) being introduced to have consistency ofrotation of the coolant pump (106) and the crankshaft (108).
15.The liquid cooled internal combustion engine (100) as claimed in claim 2,wherein the first gear (202) and being mechanically coupled to the thirdgear (206) through the second gear (204) to have consistent rotary motion.
Dated this 24th day of October 2023