Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02N—STARTING OF COMBUSTION ENGINES; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDED FOR
  • F02N15/00—Other power-operated starting apparatus; Component parts, details, or accessories, not provided for in, or of interest apart from groups F02N5/00 - F02N13/00
  • F02N15/02—Gearing between starting-engines and started engines; Engagement or disengagement thereof
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
  • B60K11/00—Arrangement in connection with cooling of propulsion units
  • B60K11/06—Arrangement in connection with cooling of propulsion units with air cooling
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B61/00—Adaptations of engines for driving vehicles or for driving propellers; Combinations of engines with gearing
  • F02B61/02—Adaptations of engines for driving vehicles or for driving propellers; Combinations of engines with gearing for driving cycles
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02N—STARTING OF COMBUSTION ENGINES; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDED FOR
  • F02N15/00—Other power-operated starting apparatus; Component parts, details, or accessories, not provided for in, or of interest apart from groups F02N5/00 - F02N13/00
  • F02N15/006—Assembling or mounting of starting devices
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H57/00—General details of gearing
  • F16H57/02—Gearboxes; Mounting gearing therein
  • F16H57/035—Gearboxes for gearing with endless flexible members
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H57/00—General details of gearing
  • F16H57/02—Gearboxes; Mounting gearing therein
  • F16H2057/0203—Gearboxes; Mounting gearing therein the gearbox is associated or combined with a crank case of an engine
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H57/00—General details of gearing
  • F16H57/02—Gearboxes; Mounting gearing therein
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H9/00—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members
  • F16H9/02—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members without members having orbital motion
  • F16H9/04—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members without members having orbital motion using belts, V-belts, or ropes
  • F16H9/12—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members without members having orbital motion using belts, V-belts, or ropes engaging a pulley built-up out of relatively axially-adjustable parts in which the belt engages the opposite flanges of the pulley directly without interposed belt-supporting members
  • F16H9/16—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members without members having orbital motion using belts, V-belts, or ropes engaging a pulley built-up out of relatively axially-adjustable parts in which the belt engages the opposite flanges of the pulley directly without interposed belt-supporting members using two pulleys, both built-up out of adjustable conical parts
  • F16H9/18—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members without members having orbital motion using belts, V-belts, or ropes engaging a pulley built-up out of relatively axially-adjustable parts in which the belt engages the opposite flanges of the pulley directly without interposed belt-supporting members using two pulleys, both built-up out of adjustable conical parts only one flange of each pulley being adjustable

Definitions

• This invention relates to an internal combustion engine having a continuously variable transmission.
• An engine used as a prime mover in 2 or 3 wheeled vehicles is typically provided with either a kick start or an electric start.
• the starting system employed in such vehicles normally has two configurations. Either the starting system operates through a one way clutch or the starting system has what is commonly known as a 'bendix' drive. In the latter case, the starter motor and bendix drive are fixed on the engine crankcase.
• the magneto is mounted on the crankshaft and rotary motion of the crankshaft is transmitted to a magneto rotor through a key. The magneto generates electricity for operation of ignition, lighting and signaling systems of the vehicle.
• the output shaft of the starter motor engages with the bendix drive, which in turn engages with the ring gear. When the starter motor is actuated, the motor drives the ring gear. This drives the crankshaft which enables the engine to start. Once the engine has attained a predetermined speed, the bendix drive disengages from the ring gear.
• CVT continuously variable transmission
• CVT is a mechanical device in which the torque transmission ratio is infinitely variable over a certain working range. This contrasts with a conventional geared transmission which has a limited number of selectable torque transmission ratios.
• a CVT automatically changes the torque transmission ratio depending on engine load and speed conditions.
• the CVT typically comprises of a driving pulley connected to a first half of a crankshaft of the engine, a driven pulley connected to wheels and a drive belt transmitting torque from the driving pulley to the driven pulley.
• the driving pulley comprises of a centrifugal mechanism that varies the torque transmission ratio depending upon the speed of the driving pulley.
• the ring gear of the starting system is provided on the same side of the engine as that on which the CVT is fitted. This side of the engine is less exposed to ingress of dust and other detritus than the magneto side of the engine where a cooling air fan may induce such substances into the engine, potentially causing damage.
• the ring gear in such an engine is mounted directly on the crankshaft or is integrally formed on parts of the CVT such as the outer half of the driving pulley of the CVT.
• crank shaft is increased.
• Such an increase in crankshaft length is detrimental to the engine since CVT pulleys get shifted away from the crankshaft bearing on the CVT side. This leads to increased load and consequent stresses on this crankshaft bearing which reduce the life of the bearing.
• the increased length of the crankshaft increases the width of the engine, increasing its bulk and possibly leading to loss of fuel economy.
• the present invention provides an internal combustion engine having a continuously variable transmission; a starting system comprising a starter motor, a ring gear and a ring gear drive operable on starting of the engine, and a crankshaft having a first section and a second section wherein the continuously variable transmission is connected to the first section of the crankshaft and the ring gear of the starting system is connected to the second section of the crankshaft distal from the continuously variable transmission.
• the first section of the crankshaft corresponds with the CVT side of the engine where the CVT is fitted.
• the second section corresponds with the non-CVT side of the engine where the magneto is typically located.
• a fan for directing cooling air over engine components such as cylinders and cylinder heads is located on this non- CVT side of the engine.
• the ring gear may be connected to a rotor of the magneto, the rotor being connected to the crankshaft of the engine.
• the ring gear may be accommodated within the width of the rotor.
• the ring gear drive may be a bendix drive of conventional construction.
• the ring gear may be connected to, or formed integral with, the magneto rotor, at a spacing from the fan as described in the Applicant's co-pending Indian Provisional Application 40/MUM/2006 filed 10 January 2006, the contents of which are hereby incorporated by reference, avoiding obstruction of cooling air flow and allowing more efficient cooling.
• a dust separator may separate the bendix drive and ring gear from the cooling air intake system and fan making dust damage to bendix drive and ring gear much less likely.
• the internal combustion engine of the invention has several potential advantages. First, a reduction in the overall width of the engine may be achieved with resultant better engine packaging. Second, it may be possible to reduce the weight of the ring gear, by accommodating it within the width of the magneto rotor, consequently reducing the weight of engine and vehicle for a given engine capacity thus achieving greater fuel economy. Stresses on crankshaft bearings may also be reduced increasing bearing life.
• Figure 1 illustrates a sectional view of a typical engine having CVT and a starter motor according to prior art.
• Figure 2 illustrates a partial view of a typical engine having CVT with ring gear integrally formed on one of the halves of the driving pulley.
• Figure 3 illustrates a sectional view of a typical engine having a CVT and start motor with bendix drive according to the invention.
• crankshaft 120 having a first section 12 and a second section 13 is assembled in crankcase 11.
• Starter motor 16 is also assembled with crankcase 11.
• crank 10 has a continuously variable transmission (CVT) 107 and CVT components such as the driving pulley 18 are mounted on the first section 12 of the crank shaft 120.
• a ring gear 14 is also connected to the first section 12 of crank shaft 120 and driven through a one way clutch arrangement 15 in a known manner.
• the ring gear 14 is driven by the starter motor 16, at the time of starting.
• Magneto rotor 41 is mounted to the second section 13 of crankshaft 120.
• Second section 13 of crankshaft 120 corresponds with a non-CVT side of engine 10.
• Cooling fan 125 is mounted to the magneto rotor 41 on this non-CVT side of engine 10.
• the crankshaft 120 has bearings 122 and 124, bearing 122 of which is subjected to increased stresses due to the load acting on first section 12 of crankshaft 120.
• FIG. 2 illustrates a partial view of a typical prior art engine 100 showing the ring gear 17 integrally formed on one of the halves of driving pulley 18 of the CVT 107.
• the starter motor 116 and bendix drive 117 are mounted on the same section of crankshaft 120 as the CVT 107. So, during starting of engine 100, the bendix drive 117 meshes with ring gear 17 driving it until the engine 100 reaches a predetermined speed at which the bendix drive 117 disengages from ring gear 17. hi such an arrangement, dust generated by movement of the CVT belt (not shown) may damage the bendix drive 117.
• Figure 3 illustrates a partial sectional view of an engine 200 according to the present invention again having a crankshaft 220 comprising a first section 22 and second section 23 assembled in crankcase 21.
• a driving pulley 31 of CVT 27 is connected to first section 22 of crankshaft 220.
• a magneto rotor 28 is connected, conventionally, to second section 23 of crankshaft 220.
• ring gear 29 co-operable with the bendix drive 26 during starting, is welded on the outer surface 28a and on the extreme inner edge 28b of magneto rotor 28.
• This location is on the non-CVT side of engine 200 distal from CVT 27 and, in particular, distal from the driving pulley 31 and belt which generates dust which could damage a bendix drive such as bendix drive 117 of Figure 2.
• the starter motor 24 is assembled in starter motor housing 25 along with bendix drive 26.
• the starter motor housing 25 is assembled to crankcase 21.
• the driving gear (not separately shown) engages with ring gear 29 when starter motor 24 is actuated, the starting system itself operating in the conventional manner.
• the location of the ring gear 29 on the non- CVT side of engine 200 makes it possible to reduce the length of first section 22 of crankshaft 220 since the width of ring gear 29 is accommodated within the width of the magneto rotor 28 mounted on the second section 23 of the crankshaft 220. Further, as driving pulley 31 of CVT 27 is shifted towards the bearing 32 by at least a value equal to the width of the ring gear 29, reducing bearing stresses, bearing 32 life may be improved. Also, the weight of ring gear 29 is reduced by mounting it on a large diameter of the outer periphery 28a of the magneto rotor 28, a diameter greater than the diameter of the crankshaft 120 where it was mounted in the prior art engine 10 shown in Figure 1.
• the bendix drive 26 may no longer be subject to damage from dust generated by the belt of CVT 27 which is located distal to it on the other side of the engine 200.
• Figure 3 also shows that the ring gear 29 and bendix drive 26 may be protected by a dust cover 50, a portion 51 of which extends between the ring gear 29 and cooling fan 225 to form a seal.
• dust and other detritus sucked into the engine 200 by cooling fan 225 is less likely to enter and damage the ring gear 29 and bendix drive 27.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Transportation (AREA)
• Transmission Devices (AREA)
• Friction Gearing (AREA)
• General Details Of Gearings (AREA)
• Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)

Applications Claiming Priority (2)

Publications (2)

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Family Applications (1)

Country Status (6)

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Citations (7)

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• 2007
  • 2007-01-05 WO PCT/IN2007/000005 patent/WO2007080602A1/en active Application Filing
  • 2007-01-05 EP EP07717865A patent/EP1971768A4/de not_active Withdrawn
  • 2007-01-05 MX MX2007009788A patent/MX2007009788A/es active IP Right Grant
  • 2007-01-05 CN CNA2007800002255A patent/CN101313145A/zh active Pending
  • 2007-01-09 TW TW096100822A patent/TW200732179A/zh unknown
  • 2007-08-28 EG EGNA2007000912 patent/EG24735A/xx active

Patent Citations (7)

Non-Patent Citations (1)

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