[DESCRIPTION] [Invention Title]

Semi Spherical Continuously Variable Transsmision [Technical Field]

<i> The present invention relates to a semispherical continuously variable transmission, and in particular to a semispherical continuously variable transmission which might be applied to a driving unit used in a bicycle, a motorcycle, a spinning wheel, a motor or the like.

<2>

[Background Art]

<3> The semispherical continuously variable transmission is an apparatus which has a compact size, lightness and module type and is adapted to maximize the proved efficiency of a conventional CVT(Continuously Variable Transmission) for applying to a light and heavy transportation unit such as a bicycle, motor scooter or the like.

<4> Here, a driving force transmission mechanism might be classified into a metallic belt type pulley continuously variable mechanism using a friction between a metallic belt and a pulley depending on a driving force transfer medium, and a hydro-static continuously variable transmission mechanism which uses a traction drive based on an EHL phenomenon by means of a viscosity of fluid, and a variable capacity pump and a motor. The above CVT is callable of allowing a user to operate in an optimum state depending on a state of an output shaft with respect to a driving force generation element such as an engine by using a mechanical characteristic that a limitless transmission ratio is continuously obtained as compared to a convention non-continuousIy variable transmission such as a manual and automatic transmission for thereby enhancing an efficiency of a driving force transmission system without any impact in a transmission which occurs in a non-contiriuously variable transmission.

<5> The vehicle CVT is designed to obtain at least above 40HP(Horse Power) of a driving force transmission, so its structure is complicated, and a lot

of volume and weight are inevitable. The present invention is directed to increasing an efficiency of a driving force use by making a vehicle CVT system in a module type and lightness and minimized structure and by applying the same to a light and heavy transportation means.

<6> The prior art proposed to a bicycle which is one of a light and heavy load transportation means.

<7> Figure 12 is a view of a major element of a friction motor CVT for a bicycle disclosed in the Korean patent registration number 10-0694878. The above CVT comprises a driving motor which has an inner spherical side formed in a curved shape along an edge of one side for thereby receiving a driving force from the pedals of a bicycle, a driven rotor which has an inner spherical side formed in a curved shape in a concave shape along an edge of one side and is engaged with a rear wheel of a bicycle for thereby outputting a driving force so that a rear wheel of a bicycle is driven, a counter rotor which has an outer spherical side formed in a curved convex shape contacting with an inner spherical side of a driving rotor and an inner spherical side of a driven motor for thereby transferring a rotational force from a driving rotor to a driven rotor, an angle varying unit which changes an angle of a rotary shaft of a counter rotor and changes a ratio of a distance from a rotary shaft of the counter rotor to a second contact point in which a driven rotor and a counter rotor contact with each other with respect to the distance from a rotary shaft of a counter rotor to a second contact point in which a driven rotor and a counter rotor contact with each other by changing an angle of a rotary shaft of the counter rotor, and a proportion pressing type pressing means which is installed in an input shaft and an output shaft with respect to the counter rotor and presses an inner spherical side of the driving rotor toward the counter rotor and presses an inner spherical side of the driven rotor toward the counter rotor in proportion to a rotation force inputted into the driven rotor.

<8> The above CVT adapts a driving force transfer method by means of an inner spherical side-outer spherical side contact which is better than a

Toroidal CVT for thereby obtaining a simple structure and a reliable transmission system, but it has too many parts for applying to a light bicycle, and its structure is complicated. Since a higher process precision is needed, manufacturing costs a lot, and there is a limit for practically using the same.

<9> As another prior art, Figure 13 is a view of major elements of a CVT for a bicycle disclosed in the Korean patent registration number 10-0351434. It is directed to a CVT for a bicycle in which a CVT operation is implemented by means of a rotary plate and a spherical body without a chain and a sprocket which are a driving mechanism of a bicycle. In the construction of the above CVT, a pair of spherical units driven by means of a driving gear, a driving gear of each spherical unit and a bevel gear are disposed in the interior of the housing of the CVT and are supported by means of bearings of a worm gear shaft, and a pressure plate pressing a spherical unit in left and right sides of the spherical unit and an output plate outputted by means of a rolling motion of the spherical unit are installed in the same opposed axis lines, so the spherical unit contacts with the pressure plate in an eccentric position being symmetrical with the output plate, and a pinion is connected with a large gear of a pressure plate and a large gear of an output plate, respectively, through a connection shaft, and a driving force of the pedal is outputted to a shaft as an output plate rotates by means of a rolling motion of the spherical unit.

<io> The above CVT for a bicycle is transmitted by means of a change of a rotation component of a spherical side in a radius range of a spherical side depending on a change of a contact angle between a rotating spherical unit and a rotation plate, which might be a relatively simple structure among the so-far developed conventional CVTs. However, since the above structure uses at least two spherical units and pressure plates, it is too big to use for a bicycle which is relatively light. The volume is too large, and its lightness is impossible.

<ii> In the above-described conventional arts, it is possible to obtain a

desired transmission function only when a shaft of a pressure plate is positioned in a center for increasing a friction force, and the CVT is positioned in an eccentric portion of a pressure plate and an output plate. So, at least two spherical units are needed, so that a small size structure and a lightness have limits.

<12>

[Disclosure] [Technical Problem]

<13> Accordingly, it is an object of the present invention to provide a semispherical CVT for a bicycle in which one semispherical unit and one eccentric support unit are installed in an eccentric portion from a center shaft of an output plate so as to obtain a module type, a lightness and a minimization of a CVT.

<i4> It is another object of the present invention to provide a CVT in which a structure is simple, and less volume and weight are obtained, and manufacturing does not cost a lot, and less impact and noise occur during a transmission, and a maintenance does not cost a lot, and a module type transmission can be manufactured. A semispherical unit is used in stead of at least two spherical units like in the conventional at, and an eccentric support unit having a roller which supports a pressing force of a semispherical unit is installed in an opposed contact point of a semispherical unit instead of a pressure plate, and the present invention can be applied to a bicycle as well as various driving means such as motorcycle, an automatic handcart, a spinning wheel or the like without a design change.

<15>

[Technical Solution]

<i6> To achieve the above objects, in a CVT(Continuously Variable Transmission) of a movable means, there is provided a semispherical CVT which comprises a circular plate shaped disk 22 which is installed in a wheel shaft 21 of a driving wheel unit 20; a semispherical unit 18 which contacts with an eccentric position in a center of the disk 22 and is rotatable by means of a

driving force input means 10; and an eccentric support unit 40 which contacts with an opposed position of a contact point of the semispherical unit 18 and has a roller 45 for supporting a pressing force of a semispherical unit. <17> A transmission adjusting unit 16 is provided in one side of the driving force input means 10 for adjusting an angle of the semispherical unit 18.

<18>

[Advantageous Effects]

<i9> the CVT according to the present invention has a simple structure and a low manufacturing cost as compared to a conventional CVT, and no impact and noise occur when the semispherical unit and disk contact based on a variable point contact, and a weight and volume might be minimized, and a transmission operation might be possible by means of a module type and a simple control. So, the present invention might be applied to a bicycle or various driving units such as a motorcycle, a motored handcart or a spinning wheel or the like. The structure is stable, and less errors occur, and a maintenance does not cost a lot.

<20>

[Description of Drawings] <2i> Figures 1 and 2 are plane views of major elements of a CVT according to the present invention, of which Figure 1 is a view of a key construction in view of a principle of the present invention, and Figure 2 is a view of a key construction in view of a construction. <22> Figure 3 is a disassembled perspective view illustrating a CVT structure according to an embodiment of the present invention. <23> Figure 4 is an assembled perspective view illustrating a CVT structure according to an embodiment of the present invention. <24> Figure 5 is a perspective view of one state that a CVT is applied to a bicycle according to the present invention. <25> Figure 6 is a perspective view of another state that a CVT is applied to a bicycle according to the present invention.

<26> Figure 7 is a plane view of a state that a CVT is applied to a bicycle according to the present invention, of a stop state when a transmission in a bicycle is performed by means of a CVT according to the present invention. <27> Figure 8 is a view of a stop state as a use state that a transmission of a bicycle is performed by means of a CVT according to the present invention. <28> Figure 9 is a view of a driving state when a transmission in a bicycle is performed by means of a CVT according to the present invention. <29> Figure 10 is a cross sectional view of a CVT according to another embodiment of the present invention. <30> Figure 11 is a view of a driving force transmission structure of a CVT according to further another embodiment of the present invention. <3i> Figure 12 is a plane view of a major construction of a conventional friction motor CVT in the conventional art. <32> Figure 13 is a plane view of a major construction of another CVT for a bicycle in the conventional art.

<33>

[Best Mode]

<34> In a CVT(Continuously Variable Transmission) of a movable means according to the present invention, a CVT comprises a circular plate shaped disk 22 which is installed in a wheel shaft 21 of a driving wheel unit 20; a semispherical unit 18 which contacts with, an eccentric position in a center of the disk 22 and is rotatable by means of a driving force input means 10; and an eccentric support unit 40 which contacts with an opposed position of a contact point of the semispherical unit 18 and has a roller 45 for supporting a pressing force of a semispherical unit.

<35>

[Mode for Invention] <36> The preferred embodiments of the present invention will be described with reference to Figures 1, 2 through 11. <37> Figures 1 and 2 are plane views of major elements of a CVT according to

the present invention, of which Figure 1 is a view of a key construction in view of a principle of the present invention, and Figure 2 is a view of a key construction in view of a construction.

<38> As shown in Figures 1 and 2, the present invention comprises a circular plate shaped disk 22 installed in a wheel shaft 21 of a driving wheel unit 20, a semispherical unit 18 which contacts with an eccentric position in a center of the disk 22 and is rotatable by means of a driving input unit 10, and an eccentric support unit 40 which has a roller 45 contacting with a contacting point opposed position of the semispherical unit 18 for thereby supporting a pressing force of the semispherical unit.

<39> The detailed construction of the above elements will be described later with reference to Figures 3 through 11. The examples of the drawings are provided for the purpose of easier understanding of the key constructions of the present invention without limiting the present invention.

<40> Figure 3 is a disassembled perspective view illustrating a CVT structure according to an embodiment of the present invention. Figure 4 is an assembled perspective view illustrating a CVT structure according to an embodiment of the present invention.

<4i> A driving input unit of a simplified and light and module type CVT according to the present invention, as shown in Figures 1, 2 through 4, comprises an input side gear 11 provided in one external side of a casing 19, a semispherical unit 18 having a circle part in an opposed side of the input side gear 11, and a transmission adjusting unit 16 which is fixed in an upper side of a vertical shaft 15 passing through the upper and lower sides of the casing 19.

<42> In addition, a ring gear 13 is horizontally disposed in an outer side of the vertical shaft 15 positioned in the interior of the casing 19. The transmission adjusting unit 16 is installed in an upper side of the casing 19.

<43> The ring gear 13 is engaged with a driving pinion 12 installed on a shaft of the input side gear 11 and a driven pinion 14 installed on a shaft

of the semispherical unit 18 in a bevel gear shape. When the driving pinion 12 rotates, the ring gear 13 rotates, and the driven pinion 14 rotates by means of the rotation of the ring gear 13.

<44> At this time, when the vertical shaft 15 rotates at a certain angle, the driven pinion 14 installed perpendicularly to the vertical shaft 15 rotates along an outer surface of the gear of the ring gear 13, and a channel shaped fixing bar 17 might be installed for supporting the shafts of the vertical shaft 15 and the driven pinion 14.

<45> The input side gear 11 is provided with a driving force of a light traffic means or a driving unit. For example, it might be connected with a pedal shaftCnot shown) of a bicycle or a medium unit of a motor, a driving force transfer such as an engine(not shown) driven by means of a combustion of gasoline and a chain or a belt or a gear. So, the construction of the input side gear 11 of the present invention is not limited even when it is connected and rotates by means of a pedal or a motor engine.

<46> In addition, the transmission adjusting unit 16 is connected with an adjusting unit for adjusting a CVT operation through a medium, for example, a transmission lever of a bicycle might be connected through a wire.

<47> Figure 5 is a perspective view of one state that a CVT is applied to a bicycle according to the present invention. Figure 6 is a perspective view of another state that a CVT is applied to a bicycle according to the present invention. Figure 7 is a plane view of a state that a CVT is applied to a bicycle according to the present invention.

<48> As shown in Figures 5 through 7, the driving input unit 10 of the CVT according to the present invention might be applied to a bicycle. For example, a support frame 30 is connected with a rear shaft of a bicycle, namely, both ends of a wheel shaft 21 which is a central shaft of the driving wheel 20, while being connected with a front shaft of a bicycle. A circular plate shaped disk 22 is installed in a center of the wheel shaft 21, and a wheel 23 contacting with the ground is provided outside the disk 22.

<49> As shown in Figure 7, the driving input unit 10 is fixed on one side of

the support frame 30 of an eccentric position with respect to the wheel shaft 21 of a center shaft of the driving wheel unit 20, and the input side gear 11 is wound by means of a chain(not shown) connected with a pedal shaft (not shown), so a driving force might be inputted by means of a pedal driving. An outer side of the semispherical unit 18 is point-contacted with an eccentric position in a center shaft of the disk 22.

<50> In the above construction, it is preferred that an eccentric support unit 40, which counteracts for supporting a pressing force of the semispherical unit 18 is installed in the other side position of the disk 22 corresponding to a contact position of the semispherical unit 18.

<5i> A contact point pressing force of the semispherical unit 18 contacting with the disk 22 might allow the disk 22 to bent or distort by means of an eccentric stress with respect to the wheel shaft 21. So as to prevent the above problems, an eccentric support unit 40 is provided in the opposite side of the disk 22 for offsetting an eccentric stress while counteracting with respect to a contact point pressing force of the semispherical unit 18.

<52> More preferably, a roller 45 might be provided in a portion contacting with the disk 22 so as to minimize a friction force which inhibits a rotation of the disk when the eccentric support unit 40 contacts with the disk 22. The roller 45 is elastically supported by means of an elastic unit.

<53> The eccentric support unit 40 includes a fixing plate 41 which is fixed in a support frame 30 of the other side in which its one end is positioned in an opposed side of the support frame 30 having the driving input unit 10, and a roller shaft 44, which is a rotation shaft of the roller 45, is installed on a movable plate 43 distanced from the fixing plate 41. A coil shaped spring 42 is disposed between the fixing plate 41 and the movable plate 43, so the roller 45 is elastically supported by means of a surface of the disk 22.

<54> Figure 8 is a view of a stop state as a use state that a transmission of a bicycle is performed by means of a CVT according to the present invention. Figure 9 is a view of a driving state when a transmission in a

bicycle is performed by means of a CVT according to the present invention.

<55> The operation of the CVT according to the present invention will be described with reference to Figures 8 and 9, so the construction of the present invention might be more clarified.

<56> As shown in Figure 8, a driving force inputted trough the one side gear 11 is transferred so as to rotate the semispherical unit 18 through a medium such as a driving pinion 12, a ring gear 13 and a driven pinion 14. At this time, when an apex, which is a center of the semispherical unit 18, contacts with the disk 22, the disk 22 does not rotate even when the semispherical unit 18 rotates.

<57> On the contrary, while a semispherical unit 18 is being rotated for a driving and transmission operation of a bicycle, when a user adjusts a transmission lever(not shown), as shown in Figures 4 and 9, the transmission adjusting unit 16 rotates a certain angle, and the vertical shaft 15 fixed in the transmission adjusting unit 16 rotates a certain angle, and the driven pinion 14 keeps rotating along with the input side gear 11 and moves at a certain angle with respect to the center point of the ring gear 13, so each contact point of the semispherical unit 18 and the disk 22 is moved outwards from the apex of the semispherical unit 18. In this process, as the disk 22 rotates, the wheel 21 finally rotates.

<58> In the above transmission operation, as the contact point of the semispherical unit 18 goes far from the apex, the revolution of the disk 22 increases, and since a linear contact is obtained by a continuous point contact during the transmission, a transmission impact or vibration does not occur. When the disk 22 contacts with the semispherical unit 18, a small level vibration by means of a rotation of the disk 22 might be damped by means of an elastic force of the spring 42 of the eccentric support unit 40, so it is possible to obtain a stable CVT operation.

<59> As it is not shown in the drawings, the roller 45 automatically rotates by means of a friction force during the rotation of the disk 22, so the present invention might be installed in a small size power generator(not

shown) for generating power by using a rotation of the roller 45.

<60> Figure 10 is a cross sectional view of a CVT according to another embodiment of the present invention while shoring a structure for generating power with a rotational force of the roller 45.

<6i> As shown in Figure 10, since a rotation unit 52 contacts with a side of the roller 45, so the rotation unit 52 is connected with a power generation shaft 51, and the power generation shaft 51 is connected with a power generator 50 installed in the fixing plate 41 of the eccentric support unit 40.

<62> The power generator 50 is rotatable by means of a cylindrical coil and a magnet which are disposed in the interior. Namely, a common electromagnet power generator might be used.

<63> In the above structure, when the roller 45 rotates, the rotation unit 52 contacting with the roller 45 rotates by means of a friction force, and the rotation motion allows the power generator 50 to generate electric power through the power generation shaft 51 for thereby lighting a lamp(not sown) installed in a front side of a bicycle.

<64> As shown in Figure 10, there is provided a small size power generator near the wheel tire. The present invention is not limited to the disclosed example. A certain rotation transmission structure for allowing the power generator 50 to generate power using the rotation of the roller 45 might be adapted, and the rotation transmission structure might be modified and amended.

<65> Figure 11 is a view of a driving force transmission structure of a CVT according to further another embodiment of the present invention. A driving force source of the driving unit is directly transferred to the ring gear 13.

<66> As shown in Figure 11, an input side gear 11, which is adapted to connected with a driving force source of the driving unit and transfers the driving force, is deleted. Instead of the above input side gear 11, a ring gear 13 is connected with the connection gear 60, and the connection shaft 60 of the connection gear 60 is connected with a driving unit such as a pedal of

a bicycle, a motor or an engine of a combustion engine, so that the driving force generated from the driving force source of the bicycle is transferred trough the connection shaft 61 and the connection gear 60 for thereby rotating the ring gear 13. At this time, the size of the connection gear 60 might be small depending on an angle rotation space of the driven pinion 14. <67> In the examples of Figures 5 through 11, the driving force input unit 10 of the CVT and the eccentric support unit 40 according to the present invention are installed in the support frame 30 of the bicycle and the driving wheel unit 20, but the driving force input unit 10 and the eccentric support unit 40 might be installed in a bicycle by means of a motored or engine driving type or might be installed in a motorcycle as a light transportation means or a handcart with a motor and a wagon. It might be adapted for adjusting a revolution for a spinning wheel or the like as a rotation driving apparatus.

<68>

[Industrial Applicability]

<69> As described above, the CVT according to the present invention has a simple structure and a low manufacturing cost as compared to a conventional CVT, and no impact and noise occur when the semispherical unit and disk contact based on a variable point contact, and a weight and volume might be minimized, and a transmission operation might be possible by means of a module type and a simple control. So, the present invention might be applied to a bicycle or various driving units such as a motorcycle, a motored handcart or a spinning wheel or the like. The structure is stable, and less errors occur, and a maintenance does not cost a lot.

<70> As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described examples are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall

within the meets and bounds of the claims, or equivalences of such meets and bounds are therefore intended to be embraced by the appended claims.