Source: http://www.allindianpatents.com/patents/215896-belt-guiding-device-for-belt-type-continuously-variable-transmission
Timestamp: 2018-05-24 10:16:03
Document Index: 216286081

Matched Legal Cases: ['art 431', 'art 432', 'art 43', 'art 431', 'art 43', 'art 43', 'art 432', 'art 43', 'art 43', 'art 431', 'art 431', 'arts 431', 'art 43', 'art432', 'art 43', 'art 43', 'art 1431', 'art 1431', 'art 1432', 'art 2432', 'arts 2431', 'art 2431', 'arts 2432', 'art 2431', 'arts 2431', 'art 2432', 'art.\n2', 'art(43']

Indian Patents. 215896:"BELT-GUIDING DEVICE FOR BELT-TYPE CONTINUOUSLY VARIABLE TRANSMISSION"
"BELT-GUIDING DEVICE FOR BELT-TYPE CONTINUOUSLY VARIABLE TRANSMISSION"
The present invention relates to a belt-guiding device for a belt-type continuously variable transmission used in a power unit of a two or three-wheeled powered vehicle etc. and more particularly relates to a new kind of belt-type continuously variable transmission belt-guiding device where abnormal oscillations of an endless belt wrapped between a drive pulley and a driven pulley are suppressed to as great an extent as possible, a belt knocking noise is reduced, and durability of the belt is increased.
The present invention relates to a belt-guiding device for a belt-type continuously variable transmission used in a power unit of a two or three-wheeled powered vehicle etc. and more particularly relates to a new kind of belt-type continuously variable transmission belt-guiding device where abnormal oscillations of an endless belt wrapped between a drive pulley and a driven pulley are suppressed to as great an extent as possible, a belt knocking noise is reduced, and durability of the belt is increased. [0002] [Prior Art]
Conventionally, for example, the disclosure of Japanese Utility Model Laid-Open No. 3-39650 is well known as a belt-type continuously variable transmission belt-guiding device. [0003]
This belt-type continuously variable transmission device is equipped with a variable diameter drive pulley provided on an engine crankshaft, a driven pulley of a variable diameter provided on an input axis of a reduction gear coupled to a drive wheel, and an endless belt wound around both pulleys. A guide roller capable of making contact with the inner surface of the belt is provided between both pulleys and a gap is formed between the guide roller and the inner surface of the belt. When the belt then oscillates abnormally, the inner surface of this belt strikes the outer surface of the guide roller and the abnormal oscillations of the belt are suppressed. [0004] |Problems To Be Solve By This Invention]
Generally, with the aforementioned belt-type continuously variable transmission, adjustment of the transmission ratio from low ratio regions (high transmission ratio regions
including idling) to top ratio regions (low transmission ratio regions) is carried out by changing the effective contact pitch diameter between these pulleys and the belts by regulating the effective diameter of the drive pulley and the driven pulley. However, the same level of knocking sound is not generated due to oscillations of the belt for all regions from low ratios to top ratios. In actual fact, there is a large belt knocking sound that causes discomfort to the ears due to relatively large belt oscillations at low ratio regions, while on the other hand, belt oscillations at top ratio regions are relatively small and the belt knocking sound is also small. 10005]
However, with the aforementioned related belt-guiding device for a belt-type continuously variable transmission, the gap between the belt and the guide pulleys is approximately the same from low ratio regions to top ratio regions and the belt makes contact with the guide roller in the same manner, even at top ratio regions where the belt knocking noise is small so as not to be particularly noticeable to the driver, causing wear on the belt and making improving durability difficult. 10006]
As the present inventions sets out to move the endless belt in parallel width-wise with respect to the drive pulley and driven pulley in accompaniment with the transmission operation, it is the object of the present invention to provide a new kind of belt-type continuously variable transmission belt-guiding device where the contact conditions between the belt and a guide member can be changed between the low ratio regions and the top ratio regions to relieve belt abnormalities, i.e. belt knocking noise due to wave oscillations can be reduced, wear on the belt can be suppressed and the durability can be improved. 10007] (Means for Solving the Problems]
In order to attain the aforementioned object, according to the invention of claim 1, a belt-guiding device for a belt-type continuously variable transmission comprising a drive pulley of variable diameter coupled to a driving side, a driven pulley of variable diameter coupled to a driven side, and an endless belt wrapped around both pulleys, with a transmission ratio that can be varied by variably controlling the wrapping diameter of both pulleys and the belt, wherein, between the drive pulley and the driven pulley, during abnormal oscillating of the belt, a guide member capable of making contact with a peripheral surface of the belt is provided and a gap is provided between the belt guide surface of the guide member and the peripheral surface of the belt facing this belt guide
surface, with this gap narrowing when the belt is in high transmission ratio regions and broadening when the belt is in low transmission ratio regions. According to this aspect, belt knocking noise due to this belt being guided by the guide member can be reduced at the time of abnormal oscillations of the belt, contact between the belt and the guide member can be avoided except for when necessary and the resilience of the belt can be improved. 10008]
In order to attain the aforementioned object, according to the invention of claim 2, in that of claim 1 the belt guide surface of the guide member has a first guide part facing the belt when the belt is in high transmission ratio regions and a second guide part facing the belt when the belt is in low transmission ratio regions, a gap between the first guide part and the peripheral surface of the belt is narrow, a gap between the second guide part and the peripheral surface of the belt is broad, and the strength of the first guide part is lower than the strength of the second guide part. According to this aspect, in addition to the above effects, the belt makes contact with the guide member in a buffered manner and the belt knocking noise can be dramatically reduced. 10009]
In order to attain the aforementioned object, according to the invention of claim 3, in that of claim 1 the first guide part is biased to one side from the position of the center of gravity occurring at a cross-section of the belt when the belt is in a high transmission ratio region. According to this aspect, in addition to the above effects, the belt is inclined so as to gradually come into contact with the guide member and belt knocking can therefore be dramatically reduced. 10010]
In order to attain the aforementioned object, according to the invention of claim 4, in that of claim 1, 2 or 3, the guide member has a belt guide surface constituted by a guide roller provided so as to be freely rotatable midway between the drive pulley and the driven pulley with the outer surface thereof facing the inner surface of the belt, with the belt guide surface being equipped with the first guide part constituted by a large diameter portion and the second guide part constituted by a flat surface of a small diameter. According to this aspect, in addition to the above results, at the time of contact between the belt and guide roller, the guide roller rotates and the friction between the belt and the guide roller is dramatically reduced. 10011]
In order to attain the aforementioned object, according to the invention of claim 5, the guide member is formed as a single body so as to project from a casing body
encompassing the belt-type continuously variable transmission and the belt guide surface facing the peripheral surface of the belt is formed from the first guide part constituted by a higher surface and a second guide prt constituted by a lower surface, with a gap between the first guide part and the peripheral surface of the belt being narrower than a gap between the second part and the peripheral surface of the belt. According to this aspect, in addition to the above effects, the guide member for guiding the belt projects from the casing body and is constituted by upper and lower fixed guides so that the number of parts and number of assembly processes can be reduced and substantial cost savings can be made.
In the following, a practical example of the present invention is described based on embodiments of the present invention shown in the attached drawings. In the following description, "front and back", "left and right", and "top and bottom" are based on the direction of travel of a motorcycle.
Accordingly, the present invention provides a belt-guiding device for a belt type continuously variable transmission comprising a drive pulley (4) of variable diameter coupled to a driving side, a driven pulley (21) of variable diameter coupled to a driven side, and an endless belt (13) wrapped around both pulleys (4,21), with a transmission
ratio that by variably controlling the wrapping diameter of both pulleys (4,
2 1 ) and the belt (,3), characterized in that
the drive pulley (4) and the driven pulley (21), during abnormal oscillating nf-tfaa-belt (13), a guide member (33; 133; 233; 333u; 333d; 433u; 433d) capable of making contact with a peripheral surface of the belt (13) is provided and a gap is provided between the belt guide surface of the guide member (33; 133; 233; 333u; 333d; 433u, 433d) and the peripheral surface of the belt (13) facing this belt guide surface, with this gap narrowing when the belt (13) is in high transmission ratio regions and broadening when the belt (13) the belt (13) is in low transmission regions wherein the belt guide surface of the guide member (33; 133; 233; 333u; 333d; 433u, 433d) has a first guide part (43 1; 143,; 243 1; 343 f, 4430 facing the belt (13) when the belt (13) is in high transmission ratio regions and a second guide part (432; 1432; 2432:3432; 4432) facing the belt (13) when
the belt (13) is in low transmission ratio regions, a gap between the first guide part and the peripheral surface of the belt is narrow, a gap between the second guide part and the peripheral surface of the belt is broad, and the strength of the first guide part is lower than the strength of the second guide part.
[Brief Description of the/Drawings]
FIG. 1 is a cross-section taken along line 1-1 of FIG. 2 of a power unit equipped with a belt-type continuously variable transmission belt-guiding device (first embodiment);
FIG. 2 is a horizontal cross-section of the power unit taken along line 2-2 of FIG. 1 (first embodiment);
FIG. 3 is a side view of the belt guiding device (first embodiment);
FIG. 4 is a longitudinal cross-section of the belt guiding device taken along line 4-4 of FIG. 3 (first embodiment);
FIG. 5 is a side view of the essential parts of a belt guiding device for a belt-type continuously variable transmission (second embodiment);
FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. 5 (second embodiment);
FIG. 7 is a side view of the essential parts of a belt guiding device for a belt-type continuously variable transmission (third embodiment);
FIG. 8 is a cross-sectional view taken along line 8-8 of FIG. 7 (third embodiment);
FIG. 9 is a side view of the essential parts of a belt guiding device for a belt-type continuously variable transmission (fourth embodiment);
FIG. 10 is a cross-sectional view taken along line 10-10 of FIG. 9 (fourth embodiment);
FIG. 11 is a side view of the essential parts of a belt guiding device for a belt-type continuously variable transmission (fifth embodiment); and
FIG. 12 is a cross-sectional view taken along line 12-12 of FIG. 11 (fifth embodiment).
First, a first embodiment of the present invention is described with reference to FIG. 1 to FIG. 4. In the first embodiment, a belt guiding device of a belt-type continuously variable transmission of the present invention is applied to a swing-type power unit for a motorcycle. |0014]
FIG. 1 is a cross-section taken along line 1-1 of FIG. 2 of a power unit equipped with the belt guiding device of the belt-type continuously variable transmission of the present invention. FIG. 2 is a horizontal cross-section of the power unit taken along line 2-2 of FIG. 1. FIG. 3 is a side view of the belt guiding device and FIG. 4 is a longitudinal cross-section of the belt guiding device taken along line 4-4 of FIG. 3. [00151
In FIG. 1 and FIG. 2, the front end of a swing-type power unit P installed with the belt-type wireless transmission is supported at a vehicle frame F of the motorcycle by a swing axis S in such a manner as to be capable of moving up and down, with the rear end thereof being suspended at the vehicle frame F via a rear cushion Cr. |0016]
The power unit P comprises an engine E, rear wheel Wr, and a belt-type continuously variable transmission B and a gear reducer G that couple and drive the engine E and the rear wheel Wr.
A casing body 1 of the power unit P is formed so as to be long in a direction from the front to the rear in order to couple the engine E and the rear wheel Wr, with the front thereof doubling as part of a crankcase 2 of the engine E so as to form the left half of the crankcase 2 of the engine E. A crank shaft 3 is supported at the crankcase 2 of the engine E in such a manner as to be freely rotatable via a pair of ball bearings 14 and 15. A variable diameter drive pulley 4 consisting of a fixed pulley half 5 and a variable pulley half 6 capable of advancing towards and retreating from the fixed pulley half 5 are provided at the left end of the crankshaft 3 that extends towards the casing body 1. A distance collar 8 that fits into the crankshaft 3 is interposed between a ramp plate 7 fixed to the crankshaft 3 in such a manner as to not be relatively rotatable and the fixed pulley half 5 and the variable pulley half 6 is supported on the distance collar 8 in such a manner as to be freely slidable. A slide pin 9 provided at the outer periphery of the ramp plate 7 engages with an axial direction guide 10 formed at the variable pulley half 6 so as to be freely slidable. As a result, the ramp plate 7 can rotate as a single body with this variable pulley half 6 while permitting sliding in the axial direction of the variable pulley half 6. A space 11 having a narrowly tapered open face facing radially outwards is formed between an inclined back surface of the variable pulley half 6 and the ramp plate 7. This space 11 contains a centrifugal weight 12. When centrifugal force operating on the centrifugal weight 12 then increases due to the rotational speed of the crankshaft 3 increasing, the centrifugal weight 12 moves radially outwards within the space 11 having the tapered surface and pushes against the variable pulley half 6. As a result, the variable pulley half 6 moves towards the left, the clearance with the fixed pulley half 5 narrows, and an endless belt 13 forming a cross-sectional V-shape between the pulley halves 5 and 6 is made to move in parallel radially outwards so that the effective pitch diameter of the belt 13 with respect to the variable diameter drive pulley 4 can be regulated. (0018|
On the one hand, a casing 16 for the gear reducer G is fixed to the rear part of the casing body 1 and a reduction gear input shaft 20 for the gear reducer G is supported between the rear part of the casing body 1 and the housing 16 so as to be freely rotatable. A variable diameter driven pulley 21 consisting of a fixed pulley half 22 and a movable pulley half 23 is supported at the reduction gear input shaft 20 and the aforementioned endless belt 12 is wrapped around the driven pulley 21. The fixed pulley half 22 is supported so as to be freely slidable in the axial direction at the reduction gear input shaft 20 and is urged in a direction towards the fixed pulley half 22 by a spring 24.
A starting clutch 25 is installed at the left end of the reduction gear input shaft 20 and a drive gear 26 for the gear reducer G is formed as a single body at the right end of the reduction gear input shaft 20. The gear reducer G is arranged within the housing 16 fixed by a plurality of bolts at the right side of the rear part of the casing body 1 and the drive gear 26 drives a drive gear 29 fixed to an axle 28 of the rear wheel Wr via a well known reduction gear mechanism 27 so that rotation of the reduction gear input shaft 20 is decelerated and this is transmitted to the rear wheel Wr. [0020]
The open face of the casing body 1 is covered by an outer cover 31 fixed by a plurality of bolts and a belt-type continuously variable transmission B comprising the drive pulley 4, the driven pulley 21 and the endless belt 13 is contained within a gearbox housing 32 encompassed by the casing body 1 and the outer cover 31. [0021]
Within the gearbox housing 32, a guide roller 33 constituting a guide member for suppressing abnormal oscillations of the belt 13 is installed at a central part between the drive pulley 4 and the driven pulley 21. As shown in FIG. 1 and FIG. 2, this guide roller 33 is arranged so as to be positioned at approximately the central part of the crankshaft 3 supporting the drive pulley 4 and the reduction gear input shaft 20 supporting the driven pulley 21. A gap at the top and bottom of the belt 13 is therefore kept substantially constant in the vicinity of the guide roller 33 even if the transmission ratio of the belt-type continuously variable transmission B changes and, as shown in FIG. 3, the line of the belt 13 changes from a low ratio band to a top ratio band. The diameter of the guide roller 33 is set in such a manner that a prescribed gap is maintained between the outer peripheral surface of the guide roller 33, i.e. the belt contact surface and the inner peripheral surface of the belt 13 so that abnormal oscillations do not occur at the belt 13. |0022]
As shown in FIG. 4, the guide roller 33 is supported at a stepped bolt 36 fixed to a boss 35 protruding towards the outer cover 31 from the inner periphery of the casing body 1 via a ball bearing 37 so as to be freely rotatable. [0023]
As shown in FIG. 3 and FIG. 4, the guide roller 33 comprises an outer 39 constituted by a resilient member of rubber etc. baked to the outer periphery of a metal inner 28 made of Fe or Al etc. A recess 40 in which the outer race of the ball bearing 37 is embedded and a grease pocket 41 for preventing grease stuck to the ball bearing 37 from
flowing out to within the inside of the casing body 1 and becoming stuck to the belt are formed at the inner surface of the inner 28. A belt guide surface is formed at the outer periphery of the outer 39 of the guide roller 33. The width in the axial direction of a belt guide surface 43 is formed so as to be equal to or slightly wider than the width of movement of the inner surface of the belt 13 while moving in parallel in a direction from left to right from a low ratio region to the top ratio region. This guide roller 33 has annular channels 44 and 45 at both left and right sides of the outer 39 consisting of rubber and an outer periphery 46. A first guide part 431 is formed at one side of the side close to the casing body 1 of the outer periphery 46 radially extending outwards and a second guide part 432 with a flat outer surface is formed at the remaining portion excluding the first guide part 43,. The second guide 432 occupies a large portion of the belt guide surface 43 and is smoothly connected to the first guide part 431 constituted by the large diameter portion by an upwardly slanting inclined surface continuing on from this second guide part. The thickness of the first guide part 43, constituted by the large diameter portion is made thinner than the second guide part 43 2 so as to be more flexible than the second guide part 432. As shown by the solid line in FIG. 4, when the belt-type continuously variable transmission B is in a low ratio region, the inner surface of the belt 13 faces the first guide part 43, constituted by the large diameter portion and, as shown by the two dots and a dashed line in FIG. 4, when the belt is in the top ratio region, the inner surface of the belt 13 faces the flat second guide part 43 2. [0024]
A cylindrical labyrinth rib 48 protrudes from the outer periphery of the boss part of the casing body 1 and this operates in cooperation with the grease pocket 41 of the guide roller 33 so as to construct a labyrinth packing for preventing grease from flowing out from the ball bearing 37 into the gearbox housing 32. 10025)
The following is a description of the operation of a first embodiment of the present invention equipped with the aforementioned configuration. |0026]
When the crankshaft 3 rotates due to the operation of the engine E, this rotation is transmitted to the reduction gear input shaft 20 via the belt-type continuously variable transmission B and transmitted on to the rear wheel Wr via the gear reducer G so that the motorcycle progresses. 10027]
Immediately as the rotation of the engine E is increased, the centrifugal weight 12
of the variable diameter drive pulley 4 of the belt-type continuously variable transmission B is subjected to centrifugal force so as to move radially outwards and the variable pulley half 6 moves in a direction so as to approach the fixed pulley half 5. As the fixed pulley halves 5 and 6 approach each other, so the width of a space V formed between the pulley halves 5 and 6 narrows and the belt 13 moves radially outwards from the drive pulley 4. When the belt 13 moves outwards, the movable pulley half 23 on the side of the drive pulley 21 presses against the belt 13 and moves to the left against the spring force of the spring 24, the width of the space V formed between the pulley halves 22 and 23 broadens, and the belt 13 moves in parallel inwards across the radial direction of the driven pulley 21. As a result, the engine E carries out continuously variable gear changing in a large ratio, low ratio region during low speeds and in a small gear ratio, top ratio region during high speeds. When the motorcycle is driven, as progress is substantial in a top ratio region, the frequency that the belt-type continuously variable transmission B employs in top ratio regions is greater than that for low ratio regions. 10028]
During normal operation of the power unit P, the endless belt 13 extends in a straight line between the variable diameter drive pulley 4 and the driven pulley 21 so as to form a prescribed gap between the inner surface of the belt 13 and the belt guide surface 43 of the guide roller 33. In this way, unnecessary contact between the belt 13 and the guide roller 33 is avoided and deterioration in the durability of the belt 13 due to frictive heating caused by such contact does not occur. |0029]
Abnormal oscillations occur at the belt 13 due to oscillations of the drive pulley 4 and the driven pulley 21, changes in the side pressure between these and the belt 13, changes in the frictional force of the belt 13 and fluctuations in the torque of the engine E etc. occur but in the case of this embodiment the inner surface of the belt 13 comes into contact with the outer surface of the guide roller 33, i.e. the belt guide surface 43 and these oscillations can be effectively suppressed. Further, the occurrence of a knocking noise due to the belt 13 coming into contact with the casing body 1 can be reduced. In particular, in this first embodiment, the occurrence of the knocking can be reduced as much as possible and the durability of the belt 13 can be dramatically improved by changing the contact conditions of the inner surface of the belt 13 and the belt guide surface 43 of the guide roller 33 in response to the operating conditions of the belt-type continuously variable transmission B. The operating conditions for this are as described below. [0030]
CD When the belt-type continuously variable transmission B is operating in a low ratio region where the transmission ratio is large, the belt 13 moves in parallel to the side of the casing body 1 as shown in FIG. 4, i.e. to the position shown by the solid line on the right of FIG. 2 and FIG. 4, and is positioned to the side with respect to the position of the center of gravity C at the cross-section of the belt 13. The inner periphery of the belt 13 faces the first guide part 431 constituted by the large diameter portion of the guide roller 33. As a result, a gap dl between the inner surface of the belt 13 and the belt guide surface 43 of the guide roller 33 becomes narrow. When the belt 13 oscillates abnormally, the belt 13 fills up this narrowed gap dl and this inner surface becomes gradually inclined so as to come into contact with the first guide part 431 constituted by the large diameter portion of the guide roller 33 or the first and second guide parts 431 and 432. The contacting surface area is then small but imbalanced contact can be made. In addition, by making the first guide part 43, with less strength so as to be more flexible, the belt 13 can be made to make dampened contact and the occurrence of belt knocking can be effectively reduced due tc the belt 13 coming into contact with the guide roller 33 in the above described synergistic action. 10031]
When the belt-type continuously variable transmission B operates in a low ratio region, the belt knocking sound due to oscillations of the belt 13 that hurt a persons ears can be reduced as much as possible in a manner which is easy for the rider to perceive. 10032)
(D When the belt-type continuously variable transmission B operates in a small transmission ratio, top ratio region.
At this time, the belt 13 moves to the side away from the side of the casing body 1, i.e. moves in parallel to the left side of FIG. 2 and 4 as shown by the two-dotted and dashed line, so that the inner surface of the belt 13 faces the second guide part432 constituted by the flat surface of the guide roller 33. The gap between the inner surface of the belt 13 and the belt guide surface 43 of the guide roller 33 is then broader than for the low ratio region. When the belt then oscillates abnormally, the frequency with which this inner surface comes into contact with the belt guide surface 43 of the guide roller 33 is substantially reduced compared with the case for the low ratio region. However, at the time of this contact, the inner surface of the belt 13 comes into contact with the flat second guide part 43, of the guide roller 33 and the contact surface area is large compared with the case of the low ratio region.
The operation of the belt 13 of the belt-type continuously variable transmission B is more stable for the top ratio region that for the low ratio region and as there are few abnormal oscillations, by making the ratio of contact with the guide roller 33 in the top ratio region small and making the surface area of contact with between the belt 13 and the guide roller 33 larger, wear due to contact with the guide roller 33 of the belt 13 can be reduced. [0034]
When the belt-type continuously variable transmission B is applied to a motorcycle power unit P, the belt-type continuously variable transmission B operates more frequently in the top ratio region when compared to the low ratio region. Wear on the belt 13 can therefore be made as low as possible while quietness is maintained across all of the operating regions ranging from low ratio regions to the top ratio region. [0035]
The following is a description of a second embodiment of the present invention with reference to FIG. 5 and FIG. 6. [0036]
FIG. 5 is a side view of the essential parts of a belt guiding device for belt-type continuously variable transmission. FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. 5 and portions that are the same as portions in the first embodiment are given the same numerals. [00371
In this second embodiment, the structure of the outer 139 of the guide roller 133 constituting a guide member differs from that of the first embodiment, i.e. a guide roller 133 is constructed by bonding an outer 139 constituted by a resilient member such as rubber etc. to the outer periphery of a metal inner 138 made of Fe and Al etc. of the same structure as the first embodiment. A plurality of teeth 150 that are the same as gear teeth are formed at the first guide part 43, constituted by the large diameter portion, of a belt guide surface 143 at the outer periphery of the outer 139. The teeth are soft and are formed so as to be easily deformed. [0038]
During operation in low ratio regions of the belt-type continuously variable transmission B, the inner surface of the belt 13 goes across an incline so as to come into contact with a first guide part 1431 constituted by the large diameter portion having the plurality of teeth 150 or come into contact with the first guide part 1431 and a second guide
part 1432. During abnormal oscillations of the belt 13, the inner surface of the belt 13 comes into contact with the belt guide surface 143 in a dampened manner so that the surface area making contact can be reduced, the knocking sound of the belt 13 making contact with the guide roller 33 can be dramatically reduced and the effective silencing of sound can be improved. [0039J
Further, when the belt-type continuously variable transmission B is driven in the top ratio region, when the belt 13 oscillates abnormally the belt 13 comes into contact with a flat second guide part 2432 in the same way as for the first embodiment. [0040]
The following is a description with reference to FIG. 7 and FIG. 8 of a third embodiment of the present invention. 10041]
FIG. Visa side view of the essential parts of a belt guiding device for a belt-type continuously variable transmission. FIG. 8 is a cross-sectional view taken along line 8-8 of FIG. 7, and portions that are the same as for the first embodiment are given the same numerals. [0042J
In the third embodiment, as a variation of the second embodiment, the structure of an outer 239 of a guide roller 322 taken as a guide member differs from that of the first embodiment, i.e. the guide roller 233 is constructed by bonding by heating the outer 239 constituted by a resilient member such as rubber etc. to the outer periphery of a metal inner 238 of Fe or Al etc. and of the same structure as that of the first embodiment. A plurality of teeth 250 of the same kind as the toothed gears are formed across the outer surface of the outer 239, i.e. across the whole of the belt guide surface 243, i.e. across first and second guide parts 2431 and 2432. With these teeth 250, portions corresponding to the first guide part 2431 are made deeper than portions corresponding to the second guide parts 2432, with any of these teeth 250 being soft and formed so as to be easily deformed. 10043]
During operation in a low ratio region of the belt-type continuously variable transmission B, the inner surface of the belt 13 straddles over so as to be inclined and come into contact with the first guide part 2431 having a plurality of teeth or the first and second belt guide parts 2431 and 2432. When the belt 13 oscillates abnormally, the inner surface of the belt 13 comes into contact with the belt guide surface 243 of the guide roller 233 in a dampened manner so that the surface area making contact can be reduced, the knocking
noise made when the belt 13 makes contact with the guide roller 233 can be dramatically reduced and the sound dampening effect can be increased. During operation in this top ratio region, the inner surface of the belt 13 comes into contact with the second guide part 2432 having the plurality of teeth 250 in a dampened manner and the knocking sound made when making soft contact with the belt 13 can be dramatically reduced. 10044]
The following is a description with reference to FIG. 9 and FIG. 10 of a fourth embodiment of the present invention. 10045]
FIG. 9 is a side view of the essential parts of a belt guiding device for the belt-type continuously variable transmission B. FIG. 10 is a cross-sectional view taken along line 10-10 of FIG. 9, and portions that are the same as for the first embodiment are given the same numerals. [0046]
The fourth embodiment differs from the first to third embodiments in that fixed guide members are used in place of the guide rollers taken as guide members in the first to third embodiments. Namely, this guide member consists of upper and lower fixed guides 333u and 333d formed as a single body so as to project inwards, i.e. in the direction of the outer cover 31 from the inner surface of the casing body 1 made of metal such as Fe and Al etc. and containing the belt-type continuously variable transmission B. These upper and lower fixed guides 333u and 333d are positioned at the central part of the drive pulley 4 and the driven pulley 21 and is positioned within the belt 13. Belt guiding surfaces 343 of the upper and lower fixed guides 333u and 333d face the inner surface of the belt 13 and come into contact with the inner surface of the belt 13 midway between the pulleys 4 and 5. This means that the gap between the belt guide surfaces 343 of the upper and lower fixed guides 333u and 333d and the inner surface of the belt 13 does not change whatever the transmission position of the belt 13. Further, as shown in FIG. 10, a flat upper surface 343, comprising a first guide part and a flat lower surface 343 2 comprising a second guide part are formed, in such a manner as to sandwich a step difference, at the belt guide surfaces 343 of the upper and lower fixed guides 333u and 333d making up the aforementioned pair that comprise the guide member. A gap d, between the inner surface of the belt 13 and the upper surface 343, is narrow and a gap d2 between the inner surface of the belt 13 and the lower surface 3432 is broader than d,. As with the first embodiment, when the belt-type continuously variable transmission B operates in the low ratio with a high transmission ratio region, the belt 13 is at the side of the casing body 1 as shown by the solid lines in
FIG. 10, and straddles the upper surface 3431 (first guide part) and the lower surface 3432 (second guide part) so that the inner surface of the belt 13 faces the upper surface 3431 (first guide part) and the lower surface 3432 (second guide part) while on the other hand, when the transmission ratio is low so as to be operating in a top ratio region, the belt 13 moves far off to the side from the casing body 1 as shown by the two-dotted and dashed line in FIG. 10 and the inner surface of the belt 13 faces the lower surface 3432. Therefore, when the belt 13 is in a low ratio region, the gap dl between the inner surface of the belt 13 and the upper and lower fixed guides 333u and 333d is narrow and when the belt is in a top ratio region, the gap d2 between the inner surface of the belt and the upper and lower fixed guides 333u and 333d becomes broad. [0047]
When the belt-type continuously variable transmission B operates in a high transmission ratio, low ratio region, the belt 13 moves in parallel to the side of the casing body 1, i.e. to the position of the solid lines in FIG. 10 so that the inner surface of the belt 13 faces the upper and lower fixed guides 333u and 333d and the gap dl between the inner surface of the belt 13 and the upper and lower fixed guides 333u and 333d becomes narrow. When the belt 13 oscillates in an abnormal manner, the inner surface of the belt 13 straddles the upper surface 343, or the upper surface 343, and the lower surface 3432 of the upper and lower fixed guides 333u and 333d so as to become inclined and gradually make contact. The surface area that makes contact is therefore small and a non-uniform contact can be made so that the occurrence of a belt knocking sound due to the belt 13 coming into contact with the guide member can be effectively reduced. 10048]
When the belt-type continuously variable transmission B is operating in a low reduction ratio, top ratio region, as shown by the two-dotted and dashed line in FIG. 10, the belt 13 moves in parallel away from the side of the casing body 1 and the inner surface of the belt 13 faces the lower surface 3432 (second guide part) of the upper and lower fixed guides 333u and 333d. As a result, the gap d2 between the inner surface of the belt 13 and the upper and lower fixed guides 333u and 333d becomes broader for low ratio regions and when the belt 13 oscillates abnormally, the frequency with which the belt 13 comes into contact with the upper and lower fixed guides 333u and 333d is small compared with the case for low ratio regions. In addition, as the inner surface of the belt 13 comes into contact with the flat lower surface 3432, the contact surface area is large compared with the case of low ratio regions and wear due to contact between the belt 13 and the upper and lower fixed guides 333u and 333d is reduced.
10049]
The following is a description with reference to FIG. 11 and FIG. 12 of a fifth embodiment of the present invention. [0050]
FIG. 11 is a side view of the essential parts of a belt guiding device for the belt-type continuously variable transmission B and FIG. 12 is a cross-section taken along line 12-12 of FIG. 11, with portions that are the same as for the first embodiment being given the same numerals. (0051]
In the fifth embodiment, the upper and lower fixed guides of the fourth embodiment are provided on the outside of the belt 13 in such a manner that upper and lower fixed guides 433u and 433d are formed as a single body so as to project inwards from the inner surface of the casing body 1 so as to be positioned midway between the drive pulley 4 and the driven pulley 21 on the outside of the endless belt 13. A higher surface 443, taken as the first guide and a lower surface 4432 taken as the second guide formed as a single body so as to be interposed by a step in the same way as the fourth embodiment at a belt guide surface 443 facing the outside surface of the belt 13. 10052]
In the fifth embodiment, at the time of abnormal oscillation of the belt 13, the outer surface of the belt 13 comes into contact with the upper and lower fixed guides 433u and 433d, with other aspects of the configuration and operation being the same as for the fourth embodiment and therefore being omitted. |0053]
A description of embodiments of the present invention is given above but the present invention is by no means limited to these embodiments and various embodiments are possible within the scope of the present invention. For example, in the above embodiments the belt-guiding device for a belt-type continuously variable transmission is used in a power unit for a motorcycle but can also be applied to other power units. Further, other items that have the same effect can also be employed as the guide member in place of the guide rollers and fixed guides. 10054] [Effects of the Invention]
According to the invention of claim 1, when abnormal oscillations occur between the drive pulley and the driven pulley in a belt-type continuously variable transmission, a guide member capable of making contact with the peripheral surface of this belt is provided
and a gap is provided between the belt guide surface of this guide member and a belt surface facing this belt guide member. This gap is then narrow when the belt is in high transmission ratio regions and broad when the belt is at low transmission ratio regions. A belt knocking noise resulting from the guiding of this belt by the guide member at times of abnormal oscillations of the belt can therefore be reduced, unnecessary contact between the belt and the guide member is avoided and the durability of the belt is improved. [0055]
According to the invention of claim 2, with that of claim 1, the belt guide surface of the guide member has a first guide part facing the belt when the belt is in a high transmission ratio region and a second guide part facing the belt when the belt is in a low transmission region. Here, the gap between the first guide part and the belt surface is narrow and the gap between the second guide part and the belt surface is broad, with the first guide part being weaker than the second guide part. As a result, the belt comes into contact with the guide portion in a dampened manner and a belt knocking noise can be dramatically reduced. [00561
According to the invention of claim 3, in that of the second claim, the first guide part is biased to one side from the position of the center of gravity occurring at a cross-section of the belt when the belt is in a high transmission ratio region. The belt therefore becomes inclined and gradually comes into contact with the guide member so that the belt knocking noise is dramatically reduced. [0057]
According to the invention of claim 4, in that of claim 1, 2 or 3, the guide member has a belt guide surface constituted by a guide roller provided so as to be freely rotatable midway between the drive pulley and the driven pulley with the outer surface thereof facing the inner surface of the belt, with the belt guide surface being equipped with the first guide part constituted by a large diameter portion and the second guide part constituted by a flat surface of a small diameter. Therefore, in addition to the above results, at the time of contact between the belt and guide roller, the guide roller rotates and the friction between the belt and the guide roller is dramatically reduced. [0058]
According to the invention of claim 5, the guide member is formed as a single body so as to project from a casing body encompassing the belt-type continuously variable transmission and the belt guide surface facing the peripheral surface of the belt is formed from the first guide part constituted by a higher surface and a second guide part constituted
by a lower surface, with a gap between the first guide part and the peripheral surface of the belt being narrower than a gap between the second guide part and the peripheral surface of the belt. Therefore, in addition to the above effects, the guide member for guiding the belt projects from the casing body and is constituted by upper and lower fixed guides so that the number of parts and number of assembly processes can be reduced and substantial cost sayings can be made.
| Key to the Reference Numerals] casing body 1
variable diameter drive pulley 4 belt 13
drive pulley 21 guide member (guide roller) 33
first guide part (large diameter portion) 43,
second guide part (flat surface) 432
guide member (guide roller) 133
first guide part (large diameter portion) 143,
second guide part (flat surface) 1432 guide member (guide roller) 233 first guide part (large diameter portion) 243, second guide part (flat surface) 2432 guide member (upper fixed guide) 333u guide member (lower fixed guide) 333d guide member (upper fixed guide) 433u guide member (lower fixed guide) 433d
1. A belt-guiding device for a belt-type continuously variable transmission
comprising a drive pulley (4) of variable diameter coupled to a driving side, a driven pulley (21) of variable diameter coupled to a driven side, and an endless belt (13) wrapped around both pulleys (4,21), with a transmission ratio that is varied by variably controlling the wrapping diameter of both pulleys (4, 21) and the belt (13), characterized in that during abnormal oscillating of the belt (13), between the drive pulley (4) and the driven pulley (21), a guide member (33; 133; 233; 333u; 333d; 433u; 433d) capable of making contact with a peripheral surface of the belt (13) is provided and a gap is provided between the belt guide surface of the guide member (33; 133; 233; 333u; 333d; 433u, 433d) and the peripheral surface of the belt (13) facing this belt guide surface, with this gap narrowing when the belt (13) is in high transmission ratio regions and broadening when the belt (13) is in low transmission regions wherein the belt guide surface of the guide member (33; 133; 233; 333u; 333d; 433u, 433d) has a first guide part (431; 1431; 2431; 3431; 4431) facing the belt (13) when the belt (13) is in high transmission ratio regions and a second guide part (432; 1432; 2432; 3432; 4432) facing the belt (13) when the belt (13) is in low transmission ratio regions, a gap between the first guide part and the peripheral surface of the belt is narrow, a gap between the second guide part and the peripheral surface of the belt is broad, and the strength of the first guide part is lower than the strength of the second guide part.
2. The belt-guiding device for a belt-type continuously variable transmission as claimed in claim 1 wherein the first guide part(43I; 1431; 2431; 3431; 4431) is biased to one side from the position of the center of gravity occurring at a region.
3. The belt-guiding device for a belt-type continuously variable transmission as claimed in claim 1 or 2 wherein the guide member (33; 133; 233) has a belt guide surface constituted by a guide roller provided so as to be freely rotatable midway between the drive pulley (4) and the driven pulley (21) with the outer surface thereof facing the inner surface of the belt (13), with the belt guide surface being equipped with the first guide part (431; 1431; 2431) constituted by a large diameter portion and the second guide part (432, 1432; 2432) constituted by a flat surface of a small diameter.
4. The belt-guiding device for a belt-type continuously variable transmission of claim 1, 2 or 3, wherein the guide member (333u, 333d; 433u, 433d) is formed as a single body so as to project from a casing body (1) encompassing the belt-type continuously variable transmission and the belt guide surface facing the peripheral surface of the belt (13) is formed from the first guide part (3433; 4431) constituted by a highter surface and a second guide part (3431; 4431) constituted by a lower surface, with a gap between the first guide part (3431; 4431) and the peripheral surface of the belt (13) being narrower than a gap between the second guide part (3432; 4432) and the peripheral surface of the belt
5. A belt-guiding device for a belt-type continuously variable transmission substantially as hereinbefore described with reference to the accompanying drawings.
566-del-1999-abstract.pdf
566-del-1999-claims.pdf
566-del-1999-correspondence-others.pdf
566-del-1999-correspondence-po.pdf
566-del-1999-description (complete).pdf
566-del-1999-drawings.pdf
566-del-1999-form-1.pdf
566-del-1999-form-13.pdf
566-del-1999-form-19.pdf
566-del-1999-form-2.pdf
566-del-1999-form-3.pdf
566-del-1999-form-6.pdf
566-del-1999-gpa.pdf
566-del-1999-petition-137.pdf
566-del-1999-petition-138.pdf
566/DEL/1999
1 MICHIO ASUMI C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, OF 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA, JAPAN.
2 JUNJI KONAKA C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, OF 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA,JAPAN
3 MITUNOBU KANEKO C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, OF 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA,JAPAN
4 YASUSHI OKAWA C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, OF 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA,JAPAN
1 H10149717 1998-05-29 Japan