CONTINUOUSLY VARIABLE TRANSMISSION

FIELD OF THE INVENTION

[0001] The present invention relates to a continuously variable transmission (CVT) for vehicles. More particularly, the present invention relates to a belt-driven CVT for transmitting a torque produced by an engine to a belt. More specifically but not exclusively, the present invention relates to a clutch device for a CVT.

BACKGROUND OF THE INVENTION

[0002] Continuously variable transmissions (CVT) are well known in the art and have many uses and provide for a smooth transition through a variety of gear ratios between the driving pulley and the driven pulley between maximum and minimum values in contrast to mechanical gear systems which only allow a few gear ratios to be mechanically selected. A CVT includes a clutch device having a driving pulley mounted to a shaft. The shaft is connected to the rotor of an engine. The driving pulley includes a pair of spaced apart pulley elements (discs or plates) which act on the driving belt positioned therebetween. The driving belt is mounted to a driven pulley. In this way the engine transfers its torque to the driven pulley. One of the two driving pulley discs or plates is caused to move towards the other one thereby pushing the belt outwardly and reducing the gear ratio between the driving pulley and the driven pulley. In essence when the clutch closes the gear ratio is reduced and when the clutch opens, the belt moves inwardly and the gear ratio increases.

[0003] Managing the movement of the movable disc or plate and in essence the opening and closing of clutch device is key to managing the inward and outward movement of the belt and thereby the gear ratio between the driving pulley and the driven pulley. The art teaches numerous ways of managing the foregoing by using a number of elements that are subject to centrifugal forces and have an effect on the movement of the movable disc or plate. These elements include weights, pressure fluids, springs and the like. [0004] Canadian Patent No. 2,102,324 issued to Claude Blackburn teaches a CVT having a pressure device rigidly connected to the movable plate. The pressure device has a pair of pressure units diametrically opposed for pressurizing fluids. The pressure unit have first and second fluid chambers separated by a movable partition. Resilient means such as springs apply a return force toward the shaft counterbalancing the centrifugal force, and a fixed partition rigidly connected to the shaft. The fixed partition also separates the first fluid chamber from the second fluid chamber. Centrifugal force urges the movable partitions away from the shaft, the fluids in the first fluid chambers are urged to circulate away from the shaft, and the fluids in the second fluid chambers are urged to circulate, generating a sliding movement of the pressure device and of the movable plate toward the fixed plate.

[0005] A drawback of known variable transmissions is that they are relatively complex structures which require greater maintenance. Another drawback of known variable transmissions is that they do not allow for a wide possibility of adjustments. For example, the tension in spring members cannot be adjusted without taking apart the device. Furthermore, weights and counterweights can only apply a limited amount of pressure. As such these same transmissions cannot be used for both small engines and large powerful engines used in larger vehicles for example, without making physical modifications to their construction.

OBJECTS OF THE INVENTION

[0006] An object of the present invention is to provide a continuously variable transmission.

[0007] An object of the present invention is to provide a clutch device for a continuously variable transmission.

SUMMARY OF THE INVENTION

[0008] In accordance with an aspect of the present invention there is provided a continuously variable transmission for transmitting a torque produced by an engine to a belt, the transmission comprising:

[0009] a shaft having a proximal end for being connected to the engine so as to be rotated thereby and an opposite distal end; and

[0010] a driving pulley mounted to the shaft so as to be rotated thereby and comprising a fixed plate fixedly mounted to the shaft and an oppositely disposed movable plate assembly slidably mounted to the shaft, the fixed plate and movable plate assembly comprising respective interfacing walls defining a groove therebetween for receiving the belt, the movable plate assembly and the shaft defining a primary chamber therebetween, the movable plate assembly comprising at least one radially disposed centrifugal chamber for receiving a pressure fluid, being in fluid communication with the primary chamber and housing a radially movable member;

[0011] wherein during rotation of the shaft, the movable plate assembly rotates therewith producing a centrifugal force urging the radially movable member to move outwardly within the centrifugal chamber thereby compressing the pressure fluid therein and causing the pressure fluid to flow into the primary chamber to so increase pressure therein as to impart a sliding movement to the movable plate assembly along the shaft towards the fixed plate decreasing the size of the groove thereby causing the belt to move outwardly along the interfacing walls thereby providing a variable transmission of torque from the engine to the belt.

[0012] In accordance with an aspect of the present invention there is provided a clutch device for a continuously variable transmission for transmitting a torque produced by an engine to a belt, the device comprising:

[0013] a shaft having a proximal end for being connected to the engine so as to be rotated thereby and an opposite distal end; and

[0014] a driving pulley mounted to the shaft so as to be rotated thereby and comprising a fixed plate fixedly mounted to the shaft and an oppositely disposed movable plate assembly slidably mounted to the shaft, the fixed plate and movable plate assembly comprising respective interfacing walls defining a groove therebetween for receiving the belt, the movable plate assembly and the shaft defining a primary chamber therebetween, the movable plate assembly comprising at least one radially disposed centrifugal chamber for receiving a pressure fluid, being in fluid communication with the primary chamber and housing a radially movable member;

[0015] wherein during rotation of the shaft, the movable plate assembly rotates therewith producing a centrifugal force urging the radially movable member to move outwardly within the centrifugal chamber thereby compressing the pressure fluid therein and causing the pressure fluid to flow into the primary chamber to so increase pressure therein as to impart a sliding movement to the movable plate assembly along the shaft towards the fixed plate decreasing the size of the groove thereby causing the belt to move outwardly along the interfacing walls thereby providing a variable transmission of torque from the engine to the belt.

[0016] In accordance with an embodiment of the invention, during operation when decreasing the rotational speed of the shaft, fluid trapped in the primary chamber flows back into the centrifugal chamber, the decrease in rotational speed causing a decrease in the centrifugal force resulting in the movable member moving inwardly within the centrifugal chamber thereby providing a space for incoming pressure fluid resulting in the movable plate assembly sliding away from the fixed plate member providing for the belt to move inwardly within said groove.

[0017] In accordance with an embodiment of the present invention, the movable plate assembly and the shaft define a secondary chamber therebetween and adjacent the primary chamber for receiving pressure fluid therein, wherein introducing pressure fluid in the secondary chamber increases pressure therein thereby, depending on the pressure within the primary chamber, providing to either impart a sliding movement of the movable plate assembly away from the fixed plate or to act against the sliding movement of the movable plate assembly towards the fixed plate

[0018] In accordance with an aspect of the present invention, there is provided a continuously variable transmission for transmitting a torque produced by an engine to a belt, the transmission comprising:

[0019] a shaft having a proximal end for being connected to the engine so as to be rotated thereby and an opposite distal end; and

[0020] a driving pulley mounted to the shaft so as to be rotated thereby and comprising a fixed plate fixedly mounted to the shaft and an oppositely disposed movable plate assembly slidably mounted to the shaft, the fixed plate and movable plate assembly comprising respective interfacing walls defining a groove therebetween for receiving the belt, the movable plate assembly and the shaft defining a chamber therebetween for receiving pressure fluid therein,

[0021] wherein introducing pressure fluid in the chamber increases pressure therein thereby imparting a sliding movement to the movable plate assembly away from the fixed plate, causing the belt to move inwardly the groove.

[0022] In accordance with an aspect of the present invention, there is provided a clutch device for a continuously variable transmission for transmitting a torque produced by an engine to a belt, the clutch device comprising:

[0023] a shaft having a proximal end for being connected to the engine so as to be rotated thereby and an opposite distal end; and

[0024] a driving pulley mounted to the shaft so as to be rotated thereby and comprising a fixed plate fixedly mounted to the shaft and an oppositely disposed movable plate assembly slidably mounted to the shaft, the fixed plate and movable plate assembly comprising respective interfacing walls defining a groove therebetween for receiving the belt, the movable plate assembly and the shaft defining a chamber therebetween for receiving pressure fluid therein,

[0025] wherein introducing pressure fluid in the chamber increases pressure therein thereby imparting a sliding movement to the movable plate assembly away from the fixed plate, causing the belt to move inwardly the groove. [0026] In accordance with an aspect of the present invention, there is provided a pressure regulating assembly for a continuously variable transmission having a shaft for being mounted to an engine to be rotated thereby and driving pulley mounted to the shaft and including a fixed plate and a movable plate for receiving a belt therebetween, the shaft comprising an opening leading to a channel for receiving fluid therein, the channel being in fluid communication with a chamber formed between the shaft and the movable plate that when pressurized imparts a movement the movable plate, the pressure regulating assembly comprising:

[0027] a housing for containing a pressure fluid;

[0028] a valve mounted to the housing for controlling fluid flow therefrom;

[0029] a conduit in fluid communication with the valve; and

[0030] a nozzle assembly mounted to the conduit and comprising a discharge element and a cork rotatably mounted to the discharge element,

[0031] wherein when the cork is mounted within the shaft channel during rotation of the shaft, the cork rotates about the discharge element, pressure fluid is provided to flow from the housing to the chamber.

[0032] Other objects, advantages and features of the present invention will become more apparent upon reading of the following non-restrictive description of non- limiting illustrative embodiments thereof, given by way of example only with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In the appended drawings, where like reference numerals denote like elements throughout and in where:

[0034] Figure 1 is a perspective view of the continuously variable transmission in accordance with a non-restrictive illustrative embodiment of the present invention; [0035] Figures 2 and 3 are front elevation view of the continuously variable transmission in accordance with a non-restrictive illustrative embodiment of the present invention;

[0036] Figure 4 is an exploded perspective view of the continuously variable transmission in accordance with a non-restrictive illustrative embodiment of the present invention;

[0037] Figure 5 is a perspective sectional view of the continuously variable transmission taken along line 5-5 of Figure 1 ;

[0038] Figure 6 is a sectional front view of the continuously variable transmission taken along line 6-6 of Figure 1 but showing the belt having moved fully outwardly of the groove defined by the driving pulley in accordance with a non-restrictive illustrative embodiment of the present invention;

[0039] Figure 7 is a sectional front view of the continuously variable transmission taken along line 7-7 of Figure 1 but showing the belt having moved fully into the groove defined by the driving pulley in accordance with a non-restrictive illustrative embodiment of the present invention;

[0040] Figure 8 is a sectional front view of the continuously variable transmission taken along line 8-8 of Figure 1 but showing the belt at a position within the groove defined by the driving pulley that is intermediate of the positions shown in Figures 6 and 8;

[0041] Figure 9 is a sectional perspective view of the continuously variable transmission taken along line 9-9 of Figure 3;

[0042] Figure 10 is a lateral elevation view of the continuously variable transmission taken along line 10-10 of Figure 3;

[0043] Figure 11 is a sectional perspective view of the continuously variable transmission taken along line 11-11 of Figure 3; [0044] Figure 12 is a perspective view of the continuously variable transmission including a pressure regulating assembly in accordance with a non- restrictive illustrative embodiment of the present invention;

[0045] Figure 13 is an enlarged view of the nozzle assembly of the pressure regulating assembly mounted to the shaft of the continuously variable transmission in accordance with a non-restrictive illustrative embodiment of the present invention; and

[0046] Figure 14 is a perspective view of the continuously variable transmission including an air pump in accordance with a non-restrictive illustrative embodiment of the present invention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0047] Generally stated, in one embodiment of the present invention there is provided CVT with a clutch device having a driving pulley mounted to a shaft connected to an engine. The driving pulley is mounted to a driven pulley via a driving belt. The pulley rotates along with the shaft. The pulley includes a fixed plate and movable plate assembly that slides along the length of the shaft. The belt is positioned between the fixed plate and the movable plate assembly. The movable plate assembly includes radially disposed centrifugal chambers with movable members therein. During rotation, these movable members are urged outwardly due to centrifugal forces thereby compressing a pressure fluid in the centrifugal chamber. The movable plate assembly and the shaft define a primary chamber. The compressed pressure fluid flows into this primary chamber increasing the pressure therein and causing the movable plate assembly to slide towards the fixed plate acting on the belt which is moved outwardly. A secondary chamber is provided to be pressurized via fluid pressure. This secondary chamber is adjacent the first chamber and acts against the pressure of the primary chamber. The foregoing provides for regulating the sliding movement of the movable plate assembly. [0048] With reference to the appended drawings, an illustrative embodiment of the present invention will be described herein so as to exemplify the invention only and by no means limit the scope thereof.

[0049] The Figures show the continuously variable transmission 10 which includes a clutch device 11 , comprising a driving pulley 12, for being connected to the rotor 13 of an engine (not shown) and for being connected, via a driving member such as belt 14 (see Figures 6, 7 and 8) to a driven pulley of the transmission drive (not shown).

[0050] With particular reference to Figure 4, the clutch device 11 includes a shaft 16 that is rotated by the engine and a pulley 12 mounted to the shaft 16 to be rotated thereby. The shaft includes a proximal end 18 for and an opposite distal end 20. As shown in Figures 6, 7 and 8 the proximal end 18 receives the rotor 13 which is fitted within a channel 19 formed by the shaft 16 (see also Figure 5). The pulley 12 includes a fixed plate and a movable plate 24. As shown in Figures 2 to 8, the fixed plate 22 is fixedly mounted to the shaft 16, near its proximal end 18, and the movable plate 24 is slidably mounted to the shaft 16. The plates 22 and 24 oppositely disposed to each other and have respective opposite interfacing walls 26 and 28. These interfacing walls 26 and 28 have opposite conical-like surfaces defining a groove 30 therebetween for receiving the belt 14, which is strapped onto an exposed section of shaft 16 between the walls 26 and 28. Each interfacing conical-like wall surface 26 and 28 defines an inner apex end 32 and an outer vertex end 34 which together generally define the inner and outer ends of the groove 30. The width of groove 30 is modifiable as will be explained herein.

[0051] As better shown in Figure 4, the plate 22 includes a central hole 36 having an annular recess 38 for receiving a seal 40 that is fixedly mounted to a corresponding recess 42 on the shaft.

[0052] The drawings show that the movable plate 24 includes a central tubular casing 44 contiguously extending from the rear side 46 of wall 28 and having a centrifugal fluid pressure assembly 48 in the form a plurality of, in this case three, tubular wall formations 50 radially and contiguously extending from casing 44 and defining respective centrifugal pressure chambers 52 (see Figures 2 and 5-10). Each of the centrifugal pressure chambers 52 is sealed by a screw cap 54; a given chamber 52 and cap 54 include respective mutually engaging threads 53 (see Figure 2) and 55 (see Figure 4) respectively. As shown through Figures 4 to 10, each chamber 52 houses therein a respective movable member in the form of tubular piston 56 having a bottom plug 58. As better shown in Figure 5, the chambers 52 are each circumscribed by a respective annular recess 60, formed within their defining walls 50 for receiving a seal ring 62. The space 64 between each cap 54 and piston 56 is filled with a pressure fluid. The number and size of the chambers 52 as well as the size and weight of the pistons 56 are predetermined depending on use. It is important to use accurate weights for specific uses in order to avoid vibration during operation of the clutch device 11. As more clearly shown in Figures 4 and 9 to 11 , the plate 24 also includes a central hole 65 that runs through the casing 44 for slidably receiving the shaft 16 therethrough. With particular attention to Figures 5, and 6 to 8, a recess 66 is formed within the sleeve wall 68 defining the central hole 64 for receiving a seal ring 70.

[0053] Turning to Figure 4, the shaft 16 includes spaced apart annular proximal and distal seals 72 and 74, respectively. The proximal seal 72 has a laterally indentured surface 73 while the distal seal 74 has a longitudinally indentured surface 75 defining recesses 76 for receiving seal rings 77 (see Figure 5).

[0054] The Figures show a pressure regulating assembly 78 is mounted on the shaft 16 and the plate 22 on the portion thereof adjacent to the shaft distal end 20. Turning now to Figures 4 to 8, the pressure regulating assembly 78 includes a main sleeve 80 defining a tubular hole 82 for slidably receiving the shaft 16 therethrough. Sleeve 80 also includes an annular plate 84 (see also Figures 1 to 3) radially extending therefrom and having apertures 86 (shown in Figure 4) corresponding to apertures 88 machined into the rim 90 (shown in Figure 4) of the casing 44 to be fastened thereto via fasteners 89. Figures 4 and 7 show a first section 8OA of the sleeve 80 extending from a first side 84A (of the annular plate 84 and being inserted within casing 44 via hole 64. A second section 8OB of the sleeve 80 extends from a second side 84B of the annular plate 84 and is external to the casing 44. As shown in Figures 1 to 8, this second section 8OB includes an enlarged distal end portion 92 for receiving a circular backing plate 94 having a central passage hole 96 (see Figure 4) for the shaft 16. Keeping with Figure 4, a recess 97 circumscribing the central passage hole 96 is formed within the plate 94 for receiving a seal ring 98 (see Figure 5). The backing plate 94 includes apertures 99 which correspond to apertures 100 machined into the rim 102 of the enlarged distal end portion 92 for being fastened thereto via fasteners 103 (see Figures 1-8).

[0055] With reference to Figures 6, 7 and 8, when assembled the shaft 16 and the sleeve 80 define primary and secondary annular pressure chambers 104 and

106, respectively, therebetween. More particularly, the primary annular chamber 104 is formed between the proximal seal 72 and the distal seal 74 and the secondary annular chamber is formed between the distal seal 74 and the backing plate 94. With respect to

Figures 9, 10 and 11 , the sleeve 80 also includes indentations or teeth 71 which mesh with indentations or teeth 73 of the shaft 16. In this way, the shaft 16 acts as a gear causing the plate 24 to turn therewith as will be further explained. As will also be further explained, the plate 24 and the sleeve 80 form part of a plate assembly 116 and as such the primary and secondary chambers 104 and 106 are defined between the plate assembly 116 and the shaft 16. Furthermore and with reference to Figures 6, 7 and 8, the internal surface 81 of the sleeve 80 having teeth 71 acts as a contact surface for the plate assembly 116 within the chamber 104.

[0056] The holes 65, 82 and 96 are coaxial providing for a common hole 108 about shaft 16 shown in Figure 6.

[0057] Figures 4, 6, 7, 8 and 11 show that a pair of longitudinal conduits 110 are formed within each of the tubular wall formations 50 adjacent to each chamber 52 and being in fluid communication therewith via a duct 112 and in fluid communication with the primary chamber 104 via a duct 114.

[0058] When connected, the movable plate 24 and the pressure regulating assembly 78 form a single piece referred herein as a plate assembly 116 (see Figures 1- 3) slidably mounted to the shaft 16 so as to slide between a distance defined by the apex end 32 of plate 24 abutting the apex end 32 of plate 22 and an annular shoulder 118 (see Figure 5) of plate 24, formed at a junction between the tubular casing 44 and the rear side 46 of wall 28 about the common central hole 108, abutting the proximal shaft seal 72. The inner end 120 (see Figure 5) of the first sleeve section 8OA is adjacent to the shoulder 118 and circumscribes the proximal shaft seal 72.

[0059] The plate assembly 116 is movable along the length of the shaft 16 as described above but it cannot rotate about the shaft 16 since the toothed surface 73 of the shaft 16 engages the complementary toothed surface 71 of the plate assembly 116 and the latter is rotatable in conjunction with the shaft 16.

[0060] Since the shaft 16 is connected to the engine rotor 13, the shaft 16 is rotated therewith in the direction shown by R. As the shaft 16 spins about its axis, the plate 22 and the plate assembly 116 will spin in conjunction therewith (as shown by arrow in Figures 9-11). This rotational movement provides centrifugal force F1 to be exerted on the pistons 56 within each chamber 50 as shown in Figures 9 and 10. The pistons 56 are thus urged to move outwardly (arrow U in Figures 6 and 7) until they abut the caps 54 (Figure 7) thereby compressing the pressure fluid within spaces 64 and pushing the fluid out of the chamber 52 as to flow into conduits 110, via ducts 112 and from there into the primary annular chamber 104 as shown by arrows P1 (Figures 6 and 7).

[0061] Referring particularly to Figures 6 and 7, the pressure fluid is thus trapped between a first seal element 12, at one longitudinal end of the primary chamber 104, formed by the primary shaft seal 72, the sleeve inner end 120 and the plate shoulder 118, and a second seal element, at an opposite longitudinal end of the primary chamber 104, defined by the distal shaft seal 74. This increases the pressure within the primary chamber 104 which imparts a sliding movement to the plate assembly 116 towards plate 22. More specifically, the direct surface area of the seal 74 is greater than that of the seal element 122, therefore greater pressure is exerted on the seal 74 and in consequence the pressure fluid exerts an outward pressure on the shaft 16 in the direction shown by F2 away from the engine. Since the shaft 16 is fixed onto the engine and cannot move in the direction of F2, this mechanical energy will act on the plate assembly 116 resulting in an opposite reaction force F3 (Figure 7) moving the plate assembly 116 in the direction of F3 towards the fixed plate 22 and narrowing the groove 30 therebetween until the respective apex ends 32 of plates 22 and 24 meet. Simultaneously, the pressure fluid also acts against the contact surface 81 within the primary chamber 104. As the pressure increases in volume within chamber 104 it increases pressure therein and needs greater space, the contact surface 81 is an encumbrance to this space and as such the pressure fluid acts against the contact surface 81 pushing it out of the primary chamber 104 which imparts a sliding movement to the plate assembly 116 towards plate 22.

[0062] As the groove 30 narrows, the walls 26 and 28 act on each side of the belt 14 causing it to slide outwardly along the walls 26 and 28 away from the apex ends 32 and towards the vertex ends 34, as shown by F4 (Figure 7). The foregoing reduces the gear or rotation ratio between the driving pulley 12 and the driven pulley. In one example, shown in Figure 6, the belt 14 is strapped around the exposed shaft 16 between plates 22 and 24 and the initial rotation ratio between the driving pulley 12 and the driven pulley is 5:1. When the belt 14 is moved upwardly as shown in Figure 8, this rotation ratio is reduced to 1 :1.

[0063] Thus the foregoing causes a variable transmission of torque from the engine to the belt 14.

[0064] The pressure fluid can include a variety of suitable fluids such as oil for example or other like as is known in the art.

[0065] The fluid circuit defined by space 64, conduit 110 ducts 112 and 114 and chamber 104 is airtight so as to avoid any loss of fluid. The fluid circuit can be filled with pressure fluid via the longitudinal conduits 110 which are sealed via screw caps 124. The casing includes an auxiliary conduit 126 (see Figures 6, 7 and 8) for filling or emptying the clutch device 11 with fluid. A cap 128 (see Figure 1) seals conduit 126. [0066] The pressure regulating assembly 78 is part of the pressure regulator of the clutch device 11 as will be explained herein. The pressure regulator includes the secondary annular chamber 106 which receives a pressure fluid to act against the pressure force F2 in the primary chamber 104 thereby resisting the force F3 and hence the movement of the plate assembly 116 towards the fixed plate 22 by providing a force directed away from the engine as shown by F5 in Figure 8. More specifically, the secondary annular chamber 106 includes a first seal element defined by the distal seal 74 at one longitudinal end and a second seal element at an opposite longitudinal end thereof defined by the backing plate 94 of the movable plate assembly 116. Pressure increase within secondary chamber 106 applies pressure against the first and second seal elements, 74 and 94, respectively. The first seal element 74 is fixed while the second seal element 94 is movable and as such is can be pushed in the direction of the shaft distal end 20 and depending on the pressure within the primary chamber 104 will either move the plate assembly 116 towards the distal end 30 or resist its movement towards the plate member 22.

[0067] Turning to Figure 12, there is shown an auxiliary pressure assembly

130 for providing pressure fluid within annular chamber 106.

[0068] The auxiliary pressure assembly 130 includes a cylindrical housing

132 for containing the pressure fluid as well as a piston 134 acting against the pressure fluid in space 136. The piston 132 is actuated by another fluid, within space 138, such as air for example. Space 138 can be filled with air via an air-opening 140 at one end 142 of the cylindrical housing 132. A short conduit 144 is mounted at the other end 146 of the cylindrical housing 132 and leads a valve 148 powered by a power source 150. A hose 152 is mounted to the valve 148 and includes a nozzle assembly 154 at its free end 156.

[0069] With particular reference to Figure 13 and general reference to

Figures 4 to 8, the nozzle assembly 154 includes a first nozzle member 158 that is fed directly from the hose 152 and is mounted to a second nozzle member 160. More specifically, the first nozzle member 158 is screwed within a side threaded channel 162 that is in a generally perpendicular relationship with a discharge channel 164 defined by an elongated discharge element or nose 166 of the second nozzle member 160. The second nozzle member 160 is mounted to a cork member 168. More specifically, the discharge nose 166 is positioned within a channel 170 defined by the cork member 168. The cork member 168 is mounted to the shaft 16 at the distal end 20 thereof. More specifically, the elongated channel 19 of the shaft 16 receives the cork member 168 which includes an annular flange 174 abutting rim 175 defined by the shaft distal end 20. The cork member 168 includes a threaded portion 176 beneath the flange 174 for mating with a complementary threaded portion 178 formed within the inner wall 180 (see Figure 5) of the shaft 16. The cork member 168 includes an aperture 182 at its free end 184.

[0070] The tip 186 of the discharge nose 166 includes a base ring 188 screwed thereon. A spring 190 is mounted on the floor 192 of the cork member 166 and a flat ring seal 194 is positioned on the spring 190. The base ring 188 engages the flat ring seal and their respective apertures are aligned with the spring 190 acting against the flat ring seal 194 thereby providing a sealing contact between rings 188 and 194. A narrowing portion of channel 170 forms a shoulder 196 which receives a bearing 200. Another bearing 198 is mounted within channel 170 near the entry hole 202 thereof. Bearings 200 and 202 are positioned along the discharge nose 194 providing for the cork member 168 to spin along with the shaft 16 during operation of the rotor 12 about the discharge nose 166.

[0071] In operation and with particular reference to Figure 8, the piston 134 within the cylindrical housing 132 is actuated by air input thereby pushing the pressure fluid in space 136 through the hose 148 since the valve 148 is open. The valve 148 is then closed and as such the pressure fluid in hose 152 cannot return back to the cylindrical housing 132. Therefore, the fluid enters the nozzle assembly 154 as shown by arrow E1 and then into the shaft channel 19 via the cork member aperture 182, as shown by arrow E2. Due to the spinning of the shaft 16 as shown by arrow C (in Figure 8) the centrifugal forces on the pressure fluid cause it to radially flow on the inner wall 180 of the shaft 16. The inner wall 180 includes a duct 204 that is in fluid communication with the second annular chamber 106. As chamber 106 fills up with pressure fluid, the area needed to contain the fluid increases since the pressure fluid pushes against the distal seal 74 and the backing plate 94 increasing the distance therebetween and applying a force F5 onto the plate assembly 116 resisting its movement towards the plate 22 to the point of nullifying this force.

[0072] More specifically, the size of the secondary chamber 106 is increased and as such the size of the primary chamber 104 is decrease, this pushes the fluid out of the primary chamber 104 and into the conduits 110 via ducts 114 and into the chambers 52 as shown by arrows P2. The fluid then pushes the pistons 56 downwardly as shown by arrow D. Since the force F2 applied against the shaft 16 and against the contact surface 81 is decreased this causes the opposite force F3 to decrease thus the plate assembly 116 is submitted to force F5 of the fluid in the secondary chamber 106 which causes the plate 24 to move away from the plate 22 as shown by arrows B which allows the belt 14 to slide along the walls 26 and 28 towards the shaft 16.

[0073] When the user opens the valve 148, the pressure on the fluid is arrested and hence the force F5 becomes null thereby causing the chamber 106 to decrease in size as the backing plate 94 moves towards the distal seal 74 with the movement of the plate assembly 116. The foregoing pushes the pressure fluid out of the chamber 106 via the duct 204 and into the shaft channel 174.

[0074] Hence when the user allows pressure fluid to fill the secondary chamber 106 as described above, the user can in effect block the action of the pressure fluid in the primary chamber 104. As such, the plate assembly 116 will not move towards the plate 22 and the belt 12 will be positioned about the shaft as is shown in Figure 6. This will allow the engine to increase in RPM to a desired speed at which the user opens the valve 148 and releases the pressure in chamber 106 providing for the plate assembly 116 to move towards the plate 22 and cause the belt 12 to move outwardly. In essence, the clutch device 11 can close immediately from an open position when the engine is already at a high RPM.

[0075] It should be noted that when opening the valve 148 the pressure fluid within the hose 152 will move back towards the cylindrical housing 132 and act against the piston 134 which will act against the pressure at its other side.

[0076] The valve is controlled by the power source 150 for opening and closing thereof. In one embodiment, the power source is connected to a manual control panel (not shown). The user can thus via this control panel preset the release time (the opening of the valve at a certain RPM). This control panel is linked to the rotor 13 in order to read its RPM.

[0077] With respect to Figure 14 the chamber 106 can be filled with air pressure via an air pump 205 providing air through an inlet 206 (see also Figures 6, 7 and 8). In one example, the air pressure is from 60 to 1000 lbs. Oil can also be mixed with air in chamber 106.

[0078] It should be noted that the various components and features described above can be combined in a variety of ways so as to provide other non- illustrated embodiments within the scope of the invention.

[0079] It is to be understood that the invention is not limited in its application to the details of construction and parts illustrated in the accompanying drawings and described hereinabove. The invention is capable of other embodiments and of being practiced in various ways. It is also to be understood that the phraseology or terminology used herein is for the purpose of description and not limitation. Hence, although the present invention has been described hereinabove by way of embodiments thereof, it can be modified, without departing from the spirit, scope and nature of the subject invention as defined in the appended claims.