Title of Invention

"LUBRICATING STRUCTURE FOR CONTINUOUSLY VARIABLE TRANSMISSON"

Abstract

[Object] To provide a lubricating structure for a continuously variable transmission, which is capable of certainly lubricating portions to be lubricated of the continuously variable transmission with a simple structure having the reduced number of parts. [Solving Means] A transmission chamber 79 for containing a continuously variable transmission T is partitioned independently from the inner space of a crank case 14. A transmission main shaft 21 of the continuously variable transmission T penetrates a cover 50 of the transmission chamber 79, and an oil pump 81 is provided at an end portion, projecting from the cover 50, of the transmission main shaft 21. The oil pump 81 sucks up a lubricating oil from an oil receiver 80 in the bottom portion of the transmission chamber 79 via an oil passage 4i formed in a casing 1, supplying the lubricating oil into the transmission chamber 79 via oil passages 211 and 212 formed in the transmission main shaft 21, and lubricates portions to be lubricated of the continuously variable transmission T. Since the lubricating system for the continuously variable transmission T is separated from the lubricating system for the engine E, it is possible to stably lubricate the continuously variable transmission T in a proper amount of the lubricating oil. Also since the oil pump 81 is provided at the end portion of the transmission main shaft 21, it is possible to make the oil pump 81 closer to the continuously variable transmission T and hence to shorten the length of the lubricating oil passage.

Full Text

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a continuously variable transmission for continuously varying the speed of rotation of a rotational input member to which a drive force of an engine is inputted and outputting the rotation whose speed is thus continuously varied, and particularly to a lubricating structure for lubricating portions to be lubricated of the continuously variable transmission. [Related Art] Continuously variable transmissions of a type in which continuously variable transmission is performed by continuously varying the contact position of a rotational transmission member in contact with a cone-shaped rotational speed-change member along a generating line of the rotational speed-change member are already known, for example, from Japanese Patent Laid-open Nos. Hei 9-177919, Hei 9-177920, and Hei 9-236161. An oil pump for lubricating such a continuously variable transmission is generally directly driven by a crank shaft of an engine or driven by an oil pump drive shaft to which the reduced rotation of the crank shaft is transmitted. [Problem to be Solved by the Invention] The above former configuration in which the oil pump is directly driven by the crank shaft, however, has a problem that it is difficult to ensure an oil passage for introducing a lubricating oil from the oil pump to the continuously variable transmission located apart from the oil pump. Also, the above latter configuration in which the oil pump is driven by the oil pump drive shaft to which the reduced rotation is transmitted has a problem that a gear or chain must be provided for transmitting a power from the crank shaft to the oil pump drive shaft, to thereby increase the number of parts and to complicate the configuration. In view of the foregoing, the present invention has been made, and an object of the present invention is to provide a lubricating structure for a continuously variable transmission, which is capable of certainly lubricating portions to be lubricated of the continuously variable transmission with a simple structure having the reduced number of parts. [Means for Solving the Problem] To achieve the above object, according to an invention described in claim 1, there is provided a lubricating structure for a continuously variable transmission, characterized in that a continuously variable transmission for continuously varying the speed of rotation of a rotational input shaft and outputting the rotation whose speed is thus continuously varied is contained in a transmission chamber independently partitioned in a crank chamber of an engine; and an oil pump for supplying a lubricating oil different from a lubrication oil for lubricating the engine into the transmission chamber is arranged in the vicinity of the rotational input shaft and driven in interlock with the rotation of the rotational input shaft. With this configuration, since the oil pump for supplying a lubricating oil to portions to be lubricated of the continuously variable transmission is arranged in the vicinity of the rotational input shaft and is driven in interlock with the rotation of the rotational input shaft, it is possible not only to make the oil pump closer to the continuously variable transmission and thereby shorten the length of a lubricating oil passage, but also to simplify the structure of a power transmission system for transmitting the rotation of the rotational input shaft to the oil pump. Further, since the lubricating system for the continuously variable transmission is independent from the lubricating system for the engine, it is possible to stably lubricate the continuously variable transmission with a proper amount of the lubricating oil. According to an invention described in claim 2, in addition to the configuration of the invention described in claim 1, the oil pump is arranged at an end portion of the rotational input shaft. With this configuration, it is possible to directly drive the oil pump by the rotational input shaft and hence to further simplify the structure of the power transmission system for transmitting the rotation of the rotational input shaft to the oil pump. According to an invention described in claim 3, in addition to the configuration of the invention described in claim 2, the lubricating oil from the oil pump is supplied to portions to be lubricated of the continuously variable transmission via oil passages formed in the rotational input shaft. With this configuration, it is possible to simply form the oil passages for supplying a lubricating oil from the oil pump to portions to be lubricated of the continuously variable transmission by making use of the rotational input shaft, and to minimize the lengths of the oil passages. According to an invention described in claim 4, in addition to the configuration of the invention described in claim 2, a gear for transmitting a drive force of the engine to the rotational input shaft is arranged between the transmission chamber and the oil pump. With this configuration, it is possible to transmit a drive force from the engine to the rotational input shaft without any interference with the oil pump. According to an invention described in claim 5, in addition to the invention described in claim 4, an oil passage through which a lubricating oil is supplied to the oil pump is formed in a casing which covers the gear from one side thereof. With this configuration, since the oil passage for supplying a lubricating oil to the oil pump is formed in the casing which covers one side of the gear for transmitting a drive force to the rotational input shaft of the continuously variable transmission, it is possible to eliminate the necessity of provision of any special member for forming the oil passage, and hence to reduce the number of parts. According to the present invention there is provided a lubricating structure for a continuously variable transmission, characterized in that a continuously variable transmission for continuously varying the speed of rotation of a rotational input shaft and outputting the rotation whose speed is thus continuously varied is contained in a transmission chamber independently partitioned in a crank chamber of an engine; and an oil pump for supplying a lubricating oil different from a lubrication oil for lubricating said engine into said transmission chamber is arranged in the vicinity of said rotational input shaft and driven in interlock with the rotation of said rotational input shaft. [Brief Description of (the Drawings] [Fig. 1} A vertical sectional view of a vehicular power unit. [Fig. 2] An enlarged view of a continuously variable transmission. [Fig. 3] An enlarged view of an essential portion of Fig. 2 (LOW ratio). [Fig. 4] An enlarged view of an essential portion of Fig. 2 (TOP ratio). [Fig. 5] A sectional view taken on line 5-5 of Fig. 2. [Fig. 6] A sectional view taken on line 6-6 of Fig. 2. [Mode for Carrying Out the Invention] Hereinafter, a mode for carrying out the present invention will be described with reference to an embodiment shown in the accompanying drawings. Figs. 1 to 6 show one embodiment of the present invention, wherein Fig. 1 is a vertical sectional view of a vehicular power unit; Fig. 2 is an enlarged view of a continuously variable transmission; Fig. 3 is an enlarged view of an essential portion of Fig. 2 (LOW ratio); Fig. 4 is an enlarged view of an essential portion of Fig. 2 (TOP ratio); Fig. 5 is a sectional view taken on line 5-5 of Fig. 2; and Fig. 6 is a sectional view taken on line 6-6 of Fig. 2. As shown in Fig. 1, a power unit P to be mounted on a motorcycle includes a casing 1 for containing an engine E, a continuously variable transmission T, and a sub-transmission R. The casing 1, which serves as a crank case of the engine E, is divided into three parts: a center casing 2, a left casing 3 joined to the left side surface of the center casing 2, and a right casing 4 joined to the right side surface of the center case 2. A crank shaft 6 supported by the center casing 2 and the left casing 3 via a pair of ball bearings 5 is connected via a connecting rod 9 to a piston 8 slidably fitted in a cylinder block 7 supported by the center casing 2 and the left casing 3. A generator 10 is provided at the left end of the crank shaft 6, the generator 10 is covered with a generator cover 11 joined to the left side surface of the left casing 3. A drive gear 12 is relatively rotatably supported around the outer periphery of the right end, extending in the right casing 4, of the crank shaft 6. The drive gear 12 is connectable to the crank shaft 6 by an automatic centrifugal clutch 13. As is apparent from Figs. 1 and 2, a driven gear 25 meshing with the drive gear 12 is fixed around a transmission main shaft 21 (rotational input shaft of the present invention) of the continuously variable transmission T. The driven gear 25 is composed of an inner gear half 26 which is spline-coupled to the transmission main shaft 21, and an outer gear half 27 which is slightly, relatively rotatably connected to the inner gear half 26 via a plurality of rubber dampers 28 and which meshes with the drive gear 12. When an engine torque transmitted from the drive gear 12 to the transmission main shaft 21 via the driven gear 25 varies, deformation of the rubber dampers 28 reduces occurrence of shock. The structure of the continuously variable transmission T will be described with reference to Fig. 2. A rotational drive member 29 having a frictional contact surface directed radially outward is spline-coupled to the outer periphery of the transmission main shaft 21, and a rotational driven member 30 having a frictional contact surface directed radially inward is relatively rotatably supported on the outer periphery of the transmission main shaft 21 via a needle bearing 22. A carrier first half 31 formed into an approximately cone-shape is relatively rotatably, axially slidably supported on the outer periphery of the transmission main shaft 21 via a needle bearing 23. A carrier second half 32 formed into an approximately cup-shape is connected to the carrier first half 31. As is apparent from Figs. 2 and 5, a torque cam mechanism 33 for locking the rotation of both the carrier halves 31 and 32 relative to the casing 1 includes a pin 34 radially planted on the outer periphery of the carrier second half 32, a roller 36 rotatably supported by the pin 34, and a guide block 35 fixed on the inner wall surface of the right casing 4 with bolts 24. The roller 36 is engaged with a guide groove 35a formed in the guide block 35. The guide groove 351 is tilted an angle α with respect to an axial line L of the transmission main shaft 21. As is apparent from Figs. 3 and 4, a plurality of supporting shafts 37 are provided in such a manner as to cross A plurality of window holes 311 formed in the carrier first half 31. A rotational speed varying member 39 is rotatably, axially slidably supported on each supporting shaft 37 via needle bearings 38. The supporting shafts 37 are arranged on generating lines of a cone centered on the axial line L of the transmission main shaft 21. The rotational speed varying member 39 has a conical first frictional transmission surface 40 and a conical second frictional transmission surface 41 which are continuous to each other at a larger-diameter portion of the rotational speed varying member 39. The first frictional transmission surface 40 is in contact with the rotational drive member 29 at a first contact portion P1, and the second frictional transmission surface 41 is in contact with the rotational driven member 30 at a second contact portion P2. As shown in Fig. 2, in the carrier second half 32 is provided a centrifugal governor 51 for axially sliding the carrier halves 31 and 32 depending on the speed of rotation of the transmission main shaft 21, thereby changing the speed varying ratio of the continuously variable transmission T. The centrifugal governor 51 includes a fixed cam member 52 fixed on the transmission main shaft 21, a movable cam member 53 which is axially slidably supported by the transmission main shaft 21 and which is rotated integrally with the fixed cam member 52, and a plurality of centrifugal weights 54 arranged between a cam plane 521 of the fixed cam member 52 and a cam plane 531 of the movable cam member 53. The movable cam member 53 and the carrier second half 32 are connected to each other via a ball bearing 55, so that they are integrally moved in the axial direction while being allowed to be rotatable relative to each other. A portion near the right end of the transmission main shaft 21 is supported, via a ball bearing 56, by a cover member 50 fixed on the center casing 2. The carrier first half 31 and the carrier second half 32 are biased leftward by an elastically repulsive force of a spring 57 contracted between the cover member 50 and the carrier second half 32. As the speed of rotation of the transmission main shaft 21 is increased, the centrifugal weights 54 are moved radially outward by the centrifugal force to press both the cam planes 521 and 531, so that the movable cam member 53 is moved rightward against the elastically repulsive force of the spring 57 and thereby the carrier second half 32 connected to the movable cam member 53 via the ball bearing 55 is moved rightward together with the carrier first half 31. As is apparent from Fig. 2, a pressure adjusting cam mechanism 60 is provided between the right end of an output gear 59 relatively rotatably supported on the outer periphery of the transmission main shaft 21 via a ball bearing 58 and the left end of the rotational driven member 30. As is apparent from Figs. 2 and 6, the pressure adjusting cam mechanism 60 is configured such that balls 61 are held between a plurality of recesses 591 formed in the right end of the output gear 59 and a plurality of recesses 301 formed in the left end of the rotational driven member 30; and a disc spring 62 is interposed between the output gear 59 and the rotational driven member 30 in such a manner as to impart a pre-load to the rotational driven member 30 for biasing the rotational driven member 30 rightward. When the rotational driven member 30 is applied with a torque to generate a relative rotation between the output gear 59 and the rotational driven member 30, the rotational driven member 30 is biased by the pressure adjusting cam mechanism 60 in the direction (rightward) where the rotational driven member 30 is separated apart from the output gear 59. The structure of the sub-transmission R will be described with reference to Fig. 2. A third reduction gear 63 is rotatably supported by a ball bearing 64 arranged between the left casing 3 and the gear 63, a needle bearing 65 arranged between the transmission main shaft 21 and the gear 63, and a ball bearing 66 arranged between the output gear 59 and the gear 63. A reduction shaft 69 is supported by the left casing 3 and the center casing 2 via a ball bearing 67 and a needle bearing 68, respectively. A first reduction gear 70 and a second reduction gear 71, which are supported on the reduction shaft 69, mesh with the output gear 59 and the third reduction gear 63, respectively. A final output shaft 631 is formed integrally with the third reduction gear 63, and a drive sprocket 73 around which an endless chain 72 is wound is provided on a portion, projecting outward from the left casing 3, of the final output shaft 63X. The rotation of the transmission shaft 21 is transmitted to a drive wheel via the output gear 59, first reduction gear 70, second reduction gear 71, third reduction gear 63, drive sprocket 73, and endless chain 72. The first reduction gear 70 is relatively rotatably supported on the reduction shaft 69, and a neutral clutch 76 configured here as a dog clutch is provided for releasably engaging the first reduction gear 70 to the reduction shaft 69. The neutral clutch 76 includes a shifter 77 axially slidably spline-coupled to the reduction shaft 69, and a fork 78 for sliding the shifter 77 in interlock with an operating member (not shown) operated by a rider. When the shifter 77 is moved leftward in the figure by the fork 78, dog teeth 77X of the shifter 77 mesh with dog teeth 70i of the first reduction gear 70, so that the first reduction gear 70 is connected to the reduction shaft 69 via the shifter 77. On the contrary, when the shifter 77 is moved rightward in the figure by the fork 78, the dog teeth 771 of the shifter 77 are separated from the dog teeth 701 of the first reduction gear 70, so that the connection between the first reduction gear 70 and the reduction shaft 69 is released. When a rider moves the motorcycle by pushing it, if rotation of a wheel is reversely transmitted from the sub-transmission R to the continuously variable transmission T, the rider must push the motorcycle with a force being large enough to overcome the frictional force at each portion of the continuously variable transmission T. In such a case, if the engagement of the neutral clutch 76 is released, the first reduction gear 70 of the sub-transmission R is separated from the reduction shaft 69 to thereby prevent the reverse transmission of a drive force to the continuously variable transmission T. As a result, the rider can move the motorcycle only by pushing it with a light force. A structure for lubricating the continuously variable transmission T and the sub-transmission R will be described below. As shown in Pig. 2, the continuously variable transmission T and the sub-transmission R are contained in a transmission chamber 79 partitioned by the left casing 3, center casing 2, and cover member 50. The transmission chamber 79 is separated from the inner space of the crank chamber 14 by sealing the outer periphery of the transmission main shaft 21 penetrating the cover member 50 with a sealing member 80. The continuously variable transmission T and the sub-transmission R are lubricated with a lubricating oil enclosed in the transmission chamber 79 and the engine E is lubricated with a lubricating oil accumulated in the crank chamber 14, and accordingly, both the lubricating oils are not mixed with each other. That is to say, the lubricating oil accumulated in the bottom portion of the crank chamber 14 is stirred by the driven gear 25 provided around the transmission main shaft 21 to lubricate each portion of the engine E. Meanwhile, the continuously variable transmission T and the sub-transmission R are lubricated with the lubricating oil circulated by an oil pump 81 provided at the end of the transmission main shaft 21. The oil pump 81 configured here as a trochoid pump includes a pump housing 83 fixed on the right casing 4 with a bolt 82, a pump cover 85 fixed on the pump housing 83 with a bolt 84, an outer rotor 86 rotatably contained in the pump housing 83, and an inner rotor 87 rotatably meshed with the inner periphery of the outer rotor 86. The inner rotor 87 is fixed to the right end of the transmission main shaft 21 penetrating the pump housing 83 via a sealing member 88. A filer chamber 91 containing an oil filer 90 is provided on the right side of an oil receiver 89 formed in the lower portion of the transmission chamber 79. The downstream side of the filter chamber 91 is communicated to a suction port 851 of the oil pump 81 via an oil passage 4i and an oil passage 831 formed in the pump housing 83. A discharge port 852 of the oil pump 81 is communicated to an oil passage 211 axially passing through the transmission main shaft 21 and also communicated to a plurality of oil passages 212 radially branched from the oil passage 211. The function of the embodiment of the present invention having the above configuration will be described below. As shown in Figs. 3 and 4, a distance A between the first contact portion Pa of the rotational drive member 29 and the axial line L of the transmission main shaft 21 is kept at a constant value irrespective of a change in speed varying ratio while a distance B between the first contact portion P1 of the rotational drive member 29 and the supporting shaft 37 becomes a variable value (BL, BT) depending on a change in speed varying ratio. Further, a distance C between the second contact portion P2 of the rotational driven member 30 and the supporting shaft 37 becomes a variable value (CL, CT) depending on a change in speed varying ratio while a distance D between the second contact portion P2 of the rotational driven member 30 and the axial line L of the transmission main shaft 21 is kept at a constant value irrespective of a change in speed varying ratio. Assuming that the speed varying ratio R is defined as R = NDR/NDN where NDR is the speed of rotation of the rotational drive member 29 and NDN is the speed of rotation of the rotational driven member 30, it is given by the following equation: R = NDR/NDN = (B/A) X (D/C) As shown in Fig. 3, upon rotation of the engine E at a low speed, the centrifugal force applied to the centrifugal weights 54 of the centrifugal governor 51 becomes small because the speed of rotation of the driven gear 25 driven by the drive gear 12 is low, so that both the carrier halves 31 and 32 are moved leftward by the elastically repulsive force of the spring 57. When the carrier first half 31 is moved leftward, the first contact portion P1 of the rotational drive member 29 is moved to the large-diameter portion side of the first frictional transmission surface 40 and thereby the distance B is increased to the maximum value BL while the second contact portion P2 of the rotational driven member 30 is moved to the small-diameter portion side of the second frictional transmission surface 41 and thereby the distance C is decreased to the minimum value CL. In this state in which the distance B is increased to the maximum value BL and the distance C is decreased to the minimum value CL, since the distances A and D are kept constant, the speed varying ratio R becomes large into a LOW ratio. On the other hand, as shown in Fig. 4, upon rotation of the engine E at a high speed, the centrifugal force applied to the centrifugal weights 54 of the centrifugal governor 51 becomes large because the speed of rotation of the driven gear 25 driven by the drive gear 12 is high, so that both the carrier halves 31 and 32 are moved rightward against the elastically repulsive force of the spring 57 by the effect of the centrifugal weights 54 moved radially outward by the centrifugal force. When the carrier first half 31 is moved rightward, the first contact portion P1 of the rotational drive member 29 is moved on the small-diameter portion side of the first frictional transmission surface 40 and thereby the distance B is decreased to the minimum value BT while the second contact portion P2 of the rotational driven member 30 is moved on the larger-diameter portion side of the second frictional transmission surface 41 and thereby the distance C is increased to the maximum value CT. In this state in which the distance B is decreased to the minimum value BT and the distance C is increased to the maximum value CT, since the distances A and D are kept constant, the speed varying ratio R becomes small into a TOP ratio. In this way, the speed varying ratio of the continuously variable transmission T can be continuously varied between the LOW ratio and the TOP ratio depending on the speed of rotation of the engine E. The control of the speed varying ratio is automatically performed by the centrifugal governor 51, and consequently, as compared with the case provided with a speed varying controller for manually performing the speed varying operation from outside the casing 1 and with the case provided with an electronic speed varying controller, it is possible to simplify the structure and hence to reduce the cost and miniaturize the continuously variable transmission T. As described above, the rotation of the rotational drive member 29 is transmitted to the rotational driven member 30 at a specific speed varying ratio R via the rotational speed varying members 39, and the rotation of the rotational driven member 30 is transmitted to the output gear 59 via the pressure adjusting cam mechanism 60. At this time, if there occurs a relative rotation between the rotational driven member 30 and the output gear 59 due to a torque applied to the rotational driven member 30, the rotational driven member 30 is biased by means of the pressure adjusting cam mechanism 60 in the direction where the rotational driven member 30 is separated from the output gear 59. The biasing force co-operates with the biasing force of the disc spring 62 to generate a surface pressure acting for bringing the first contact portion P1 of the rotational drive member 29 in press-contact with the first frictional transmission surface 40 and to generate a surface pressure acting for bringing the second contact portion P2 of the rotational driven member 30 in press-contact with the second frictional transmission surface 41. Incidentally, although the carrier second half 32 is intended to be rotated around the transmission main shaft 21 by a transmission torque reaction of the rotational drive member 29 during speed varying operation of the continuously variable transmission T, the transmission torque reaction is received by engagement of the roller 36 of the torque cam mechanism 33 supported by the carrier second half 32 with the guide grooves 35: formed in the guide block 35, so that the carrier halves 31 and 32 are allowed not to be rotated but to be slid in the axial direction. in the case where the engine torque is rapidly increased for rapid acceleration during running of the vehicle, the transmission torque reaction applied to the carrier second half 32 is increased along with the rapid increase in engine torque. As a result, as shown in Fig. 5, the roller 36 is pressed on the wall surface of the tilted guide groove 351 at a load F, and the carrier second half 32 is biased leftward in Fig. 2 (on the LOW ratio side) by a component F1 of the load F in the direction of the guide groove 35}. That is to say, the speed varying ratio is automatically changed on the LOW ratio side by the operation of the torque cam mechanism 33, so that a so-called kick down effect is attained to thus effectively accelerate the vehicle. The control of speed varying ratio upon kick-down can be automatically performed depending on a change in engine torque, without provision of any special speed varying controller, by the torque cam mechanism 33, so that it is possible to simplify the structure and hence to reduce the cost and miniaturize the continuously variable transmission T. Also the varying characteristic of the speed varying ratio can be easily adjusted only by changing the shape of the guide groove 35X of the torque cam mechanism 33. When the oil pump 81 is driven by the transmission main shaft 21 during operation of the continuously variable transmission T and the sub-transmission R, the lubricating oil lifted from the oil receiver 89 in the bottom portion of the transmission chamber 79 via the oil filter 90, oil passage 4} of the right casing 4, oil passage 831 of the pump housing 83, and suction port 851 of the pump cover 85 is supplied in the transmission chamber 79 via the discharge port 852 of the pump cover 85 and the oil passages 2l1 and 212 of the transmission main shaft 21. The lubricating oil supplied to the transmission chamber 79 lubricates the first and second frictional transmission surfaces 40 and 41 of each rotational speed varying member 39 of the continuously variable transmission T and meshing portions of the bearings and gears of the continuously variable transmission T and the sub-transmission R, and then circulates back to the oil receiver 89. In this way, since the lubricating system for the continuously variable transmission T and the sub-transmission R is provided independently from the lubricating system for the engine E, it is possible to stably lubricate the continuously variable transmission T and the sub-transmission R with a proper amount of the lubricating oil. Also since the oil pump 81 is provided at the end portion of the transmission main shaft 21 and is directly driven by the transmission main shaft 21, as compared with the case in which the oil pump 81 is driven by the crank shaft 6, it is possible to make the oil pump 81 closer to the continuously variable transmission T and hence to shorten the length of the lubricating oil passage, and also to simplify the structure of the power transmission system for transmitting the rotation of the transmission main shaft 21 to the oil pump 81. In particular, since the lubricating oil passage 211 and 212, and 41 are formed in the transmission main shaft 21 for driving the oil pump 81 and in the right casing 4 for supporting the oil pump 81 respectively, it is possible to eliminate the necessity of provision of any special member for forming the oil passages, and hence to reduce the number of parts. Since the driven gear 25 for transmitting a drive force to the transmission main shaft 21 of the continuously variable transmission T is provided outside the cover member 50 for partitioning the transmission chamber 79, it is possible to prevent the continuously variable transmission T and the transmission chamber 79 from being enlarged by provision of the driven gear 25, and to change the speed varying ratio of the drive force inputted to the transmission main shaft 21 by freely setting the dimension of the driven gear 25 irrespective of the capacity of the transmission chamber 79. While the embodiment of the present invention has been described in detail, such description is for illustrative purposes only, and it is to be understood that various changes in design may be made without departing from the scope of the present invention. For example, the present invention can be applied not only to the continuously variable transmission having the structure of the type described in the embodiment but also to a continuously variable transmission having a structure of any type. [Effect of the Invention] According to the invention described in claim 1, since the oil pump for supplying a lubricating oil to portions to be lubricated of the continuously variable transmission is arranged in the vicinity of the rotational input shaft and is driven in interlock with the rotation of the rotational input shaft, it is possible not only to make the oil pump closer to the continuously variable transmission and shorten the length of a lubricating oil passage but also to simplify the structure for a power transmission system of transmitting the rotation of the rotational input shaft to the oil pump. Also since the lubricating system for the continuously variable transmission is independent from the lubricating system for the engine, it is possible to stably lubricate the continuously variable transmission with a proper amount of the lubricating oil. According to the invention described in claim 2, it is possible to directly drive the oil pump by the rotational input shaft, and hence to further simplify the structure of the power transmission system for transmitting the rotation to the oil pump. According to the invention described in claim 3, it is possible to simply form the oil passages for supplying a lubricating oil from the oil pump to portions to be lubricated of the continuously variable transmission by making use of the rotational input shaft, and to minimize the lengths of the oil passages. According to the invention described in claim 4, it is possible to transmit a drive force to the rotational input shaft without any interference with the oil pump. According to the invention described in claim 5, since the oil passage for supplying a lubricating oil to the oil pump is formed in the casing which covers one side of the gear for transmitting a drive force to the rotational input shaft of the continuously variable transmission, it is possible to eliminate the necessity of provision of any special member for forming the oil passage, and hence to reduce the number of parts. [Explanation of Symbols] 1: casing, 41: oil passage, 14: crank chamber, 21: transmission main shaft (rotational input shaft), 211: oil passage, 212: oil passage, 25: driven gear (gear), 79: transmission chamber, 81: oil pump, E: engine, T: continuously variable transmission WE CLAIM : 1. A lubricating structure for a continuously variable transmission, characterized in that a continuously variable transmission (T) for continuously varying the speed of rotation of a rotational input shaft (21) and outputting the rotation whose speed is thus continuously varied is contained in a transmission chamber (79) independently partitioned in a crank chamber (14) of an engine (E); and an oil pump (81) for supplying a lubricating oil different from a lubrication oil for lubricating said engine (E) into said transmission chamber (79) is arranged in the vicinity of said rotational input shaft (21) and driven in interlock with the rotation of said rotational input shaft (21). 2. A lubricating structure for a continuously variable transmission as claimed in claim 1, wherein said oil pump (81) is arranged at an end portion of said rotational input shaft (21). 3. A lubricating structure for a continuously variable transmission as claimed in claim 2, wherein the lubricating oil from said oil pump (81) is supplied to portions to be lubricated of said continuously variable transmission (T) via oil passages (211, 2 12) formed in said rotational input shaft (21). 4. A lubricating structure for a continuously variable transmission as claimed in claim 2, wherein a gear (25) for transmitting a drive force of said engine (E) to said rotational input shaft (21) is arranged between said transmission chamber (79) and said oil pump (81). 5. A lubricating structure for a continuously variable transmission as claimed in claim 4, wherein an oil passage (41) through which a lubricating oil is supplied to said oil pump (81) is formed in a casing (1) which covers said gear from one side thereof. 6. A lubricating structure for a continuously variable transmission substantially as herein described with reference to the accompanying drawings. .

Documents:

176-del-1999-abstract.pdf

176-del-1999-claims.pdf

176-del-1999-correspondence-others.pdf

176-del-1999-correspondence-po.pdf

176-del-1999-description (complete).pdf

176-del-1999-drawings.pdf

176-del-1999-form-1.pdf

176-del-1999-form-13.pdf

176-del-1999-form-19.pdf

176-del-1999-form-2.pdf

176-del-1999-form-3.pdf

176-del-1999-form-4.pdf

176-del-1999-form-6.pdf

176-del-1999-gpa.pdf

176-del-1999-petition-137.pdf

176-del-1999-petition-138.pdf