Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
  • F01B9/00—Reciprocating-piston machines or engines characterised by connections between pistons and main shafts and not specific to preceding groups
  • F01B9/04—Reciprocating-piston machines or engines characterised by connections between pistons and main shafts and not specific to preceding groups with rotary main shaft other than crankshaft
  • F01B9/06—Reciprocating-piston machines or engines characterised by connections between pistons and main shafts and not specific to preceding groups with rotary main shaft other than crankshaft the piston motion being transmitted by curved surfaces
• • 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
  • F02B57/00—Internal-combustion aspects of rotary engines in which the combusted gases displace one or more reciprocating pistons
  • F02B57/08—Engines with star-shaped cylinder arrangements
• • 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
  • F02B75/00—Other engines
  • F02B75/16—Engines characterised by number of cylinders, e.g. single-cylinder engines
  • F02B75/18—Multi-cylinder engines
  • F02B75/22—Multi-cylinder engines with cylinders in V, fan, or star arrangement
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
  • F01B9/00—Reciprocating-piston machines or engines characterised by connections between pistons and main shafts and not specific to preceding groups
  • F01B9/04—Reciprocating-piston machines or engines characterised by connections between pistons and main shafts and not specific to preceding groups with rotary main shaft other than crankshaft
  • F01B9/06—Reciprocating-piston machines or engines characterised by connections between pistons and main shafts and not specific to preceding groups with rotary main shaft other than crankshaft the piston motion being transmitted by curved surfaces
  • F01B2009/061—Reciprocating-piston machines or engines characterised by connections between pistons and main shafts and not specific to preceding groups with rotary main shaft other than crankshaft the piston motion being transmitted by curved surfaces by cams
  • F01B2009/066—Tri-lobe cams
• • 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
  • F02B75/00—Other engines
  • F02B75/02—Engines characterised by their cycles, e.g. six-stroke
  • F02B2075/022—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
  • F02B2075/025—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle two
• • 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
  • F02B75/00—Other engines
  • F02B75/16—Engines characterised by number of cylinders, e.g. single-cylinder engines
  • F02B75/18—Multi-cylinder engines
  • F02B2075/1804—Number of cylinders
  • F02B2075/184—Number of cylinders ten

Definitions

• This invention relates to machines having reciprocating pistons such as internal combustion engines.
• the present invention is a development of the rotary engine disclosed in Australian patent specification 473,864.
• a machine comprising an outer casing having chambers formed therein, a piston within each chamber, a central drive shaft, and transmission means for transmitting motion between the pistons and the drive shaft, said transmission means including a rotor carrier mounted on the drive shaft, a plurality of lobed rotors rotatably mounted on the rotor carrier for rotation about axes parallel to and equidistant from the drive shaft, the lobes of the rotors sequentially contacting the pistons during the radially outer portion of each stroke of the pistons, and means providing positive connection between each piston and the drive shaft at least at the radially outer end portion of each stroke of the piston and at least at the radially inner end portion of the stroke of the piston.
• the positive connection means includes first connection means providing a detachable positive connection between each piston and the drive shaft at least at the radially outer end portion of each stroke of the piston, and second connection means providing a detachable positive connection between each piston and the drive shaft at least at the radially inner end portion of the stroke of the piston.
• a rotary machine according to the invention is particularly applicable as an engine in which case it further comprises means for causing reciprocation of the pistons in their respective chambers in a desired sequence thereby to cause the rotors to rotate about their axes and about the drive shaft axis to thereby impart rotation to the drive shaft.
• said means for causing reciprocation of the pistons includes means for causing internal combustion in said chambers in said desired sequence.
• the first connection means serves to prevent radial separation between each piston and the particular rotor lobe with which it is in contact as the piston arrives at and leaves the radially outer end of its stroke in circumstances (such as cranking and the situation commonly termed over ⁇ run where a vacuum is induced in the combustion chamber following closure of the fuel/air throlling device) when there is either no effective load, or a negative load, on the piston.
• the first connection means co ⁇ operates with the second connection means to provide a connection between the piston and the drive shaft to effect movement of the piston in the radially inward direction in circumstances when there is either no effective load, or a negative load, on the piston.
• the first connection means comprises at least one first projecting member mounted on each piston and adapted to locate in a groove formed in each particular rotor ' lobe with which the piston makes contact.
• the second connection means comprises a cam member carried on the central drive shaft, and at least one second projecting member mounted on each piston and adapted to locate in a respective groove formed in the cam, whereby location of said at least one second projecting member in the groove effects said position connection between the piston and the drive shaft.
• the cam member is provided with a cam surface at its outer periphery, each of the pistons being adapted to frictionally engage the cam when the piston- is under positive load.
• the cam serves to limit the extent of radially inward movement of each piston when it is under positive load. This arrangement also ensures that the second connection means is only operative to apply a driving force to the piston when there is no effective load, or a negative load, on the piston.
• the cam is formed integrally with the rotor carrier, the outer periphery of the rotor carrier defining the cam surface.
• each piston which is contacted by the rotor lobes is concave.
• portion of each piston which engages the cam is convex.
• Fig. 1 is a schematic front elevation of a reciprocating piston machine in the form of an internal combustion engine, with various parts of the engine cut away.
• Fig. 2 is a schematic part-sectional side elevation of the embodiment of Fig. 1,
• Fig. 3 is an exploded view of the rotor carrier, lobed rotors and one piston.
• Fig. 4 is a schematic diagram of the machine shown in Figs. 1, 2 and 3 indicating the general principles of operation of the machine.
• Fig. 5 is a schematic view of the machine showing the rotor carrier and the lobed rotors engaged against the radius at the bottom of some of the pistons-.
• Fig. 6 is a view similar to Fig. 5 showing the upper pins of the pistons engaged in the recessed contours of the lobed rotors; and.
• Fig. 7 is a view similar to Fig. 6 showing the lower pins of the pistons engaged in the recessed contours on the outer faces of the rotor carrier.
• the embodiment of the reciprocating piston machine shown in the drawings is in the form of an internal combustion engine employing a two-stroke cycle.
• the engine comprises a substantially cylindrical outer casing 1 within which is formed a plurality of chambers 3 each having a piston 5 therein.
• a working space 7 of variable volume is defined between each chamber 3 and the piston 5 therein.
• the volume of each working space 7 varies with reciprocatory movement of the respective piston.
• An inlet means 8 including an inlet port 9 is provided for admitting a combustible mixture into the working space.
• An exhaust means 11 including an exhaust port 12, is provided for exhausting spent products of combustion from the working space.
• a sparking means 15 is provided for igniting compressed combustible mixture in the working space 7.
• a transmission means is provided for transmitting motion between the pistons 5 and a central drive shaft 17 whereby on reciprocation of the pistons in their chambers in a desired sequence (according to the firing order of the engine) rotation is imparted to the drive shaft.
• the transmission means of tjiis embodiment of the invention includes a rotor carrier 19 mounted on the drive shaft 17 for rotation therewith.
• the rotor carrier supports a plurality of lobed rotors 21 for rotation about axes 23 parallel to and equidistant from the drive shaft 17.
• the rotors 21 are mounted on the rotor carrier 19 by means of respective shafts 25 supported between a pair of spaced plate members 27.
• the outer periphery of the rotor carrier 19 defines a cam 31.
• the profile of the cam is in three sections 33 each of which extends between two adjacent rotors 21, as shown in Fig. 1.
• the cam profile is defined by the outer periphery of the two spaced plate members 27 which together form the rotor carrier.
• each piston 5 has a body 35 and a pair of diametrically opposed leg portions 37 at the radially inner end of the body.
• the leg portions 37 are formed integrally with the body of the piston.
• the piston has a lobe engaging portion 39.
• the lobe engaging portion 39 is concave.
• shoulders 41 On the inner side of the leg portions 37 of the piston there are provided shoulders 41 the faces 43 of which define a follower for the cam 31.
• the faces 43 of the shoulders 41 are of convex configuration and each is adapted to frictionally engage the outer periphery of one of the plate members 27.
• the central drive shaft 17 rotates in one direction and the lobed rotors 21 rotate about their respective axes 23 in the opposite direction.
• Each lobe 29 of each rotor contacts the lobe engaging portion 39 of every third piston.
• the lobe exerts a radially outward force on the piston thereby to cause the piston to undergo a compression stroke.
• the subsequent power stroke of the piston applies a radially inward force on the rotor lobe.
• This radially inward force on the rotor lobe causes the rotor to rotate about its respective axis 23 and also about the drive shaft axis to thereby impart rotation to the drive shaft.
• the rotor lobe subsequently moves away from the piston and the rotor advances towards the next piston.
• the particular cam section 33 trailing the rotor comes into contact with the convex cam follower defined by the two shoulder faces 43 formed on the piston.
• the piston rides along the moving cam section 33 until it is engaged by one of the lobes of the next rotor.
• the engine is provided with a first connection means for preventing radial separation between each piston and the particular rotor lobe with which it is in contact as the piston arrives at and leaves the radially outer end of its stroke. In the absence of the first connection means, such separation may occur during cranking and over-running of the engine and could well be damaging to the engine.
• the engine is also provided with second connection means which in conjunction with the first connection means establishes a positive mechanical connection between the piston and the drive shaft in order to move the piston in the radially inward direction at required times as the drive shaft rotates, in circumstances where there is no effective load on the piston.
• the first connection means comprises first projecting members in the form of a pair of opposed pins 45, each pin being mounted on and projecting inwardly from a respective one of the piston leg portions 37.
• the first connection means further comprises a pair of grooves 47 formed one on each side face 49 of each rotor lobe.
• the grooves 47 on each rotor lobe are adapted to receive the pins 45 on each piston when the rotor lobe moves into contact with the piston.
• the grooves 47 each have a lead-in section 47a, an intermediate section 47b and a lead-out section 47c, . as shown in Fig. 1.
• the second connection means comprises second projecting members in the form of a pair of opposed pins
• the second connection means further comprises a pair of grooves 53 corresponding to each cam section 33, the grooves being located one on the outer side face of each plate member 27, inwardly of the cam section.
• the grooves 53 have a lead-in point and a lead-out point.
• the grooves 53 corresponding to each cam section 33 are adapted to receive the pins 51 on each piston before the cam section moves into contact with the piston.
• Fig. 5 shows the position of each piston 5 within its cylinder or chamber 3 and the engagement of lobes 29a, b, c, d and e against the concave lobe engaging portions 39 of the pistons 5a, d, e, g and h.
• Fig. 7 shows the connection between the lower pins 51 which project inwardly from the leg portions 37 of the pistons 5 (the “second connection means” of the embodiment shown in Figs. 1 to 3) and the grooves 53 on the outer side faces of the plate members 27.
• a combustible fuel mixture is introduced into -working space.
• the piston is at or near the radially outermost position (i.e. top-dead- ⁇ entre position) the compressed fuel mixture in the working space is ignited by the sparking means 15.
• the piston exerts a radially inward force on the rotor lobe which causes the rotor to rotate about its axis 23 and about the drive shaft axis to thereby impart rotation to the drive shaft.
• the pins 45 traverse the grooves 47 towards the lead-out section 47c.
• the pins 51 commence engagement with the grooves 53 corresponding to the particular cam section 33 trailing at the end of the rotor (which engagement takes effect at an angle of advance of approximately 12 degrees).
• the piston then continues its movement towards the bottom- dead-centre position. The cycle is then repeated.
• the first and second connection means have no influence on the movement of the piston with the exception that the first connection means prevents over-travel of the piston at its top-dead- centre position.
• the cam limits the radially inward extent of movement of the piston thereby to define its bottom-dead-centre position.
• the first and second connection means provide positive connection between the piston and the drive shaft in order to move the piston in the radially inward direction from its top-dead-centre position to its bottom- dead-centre position.
• first and second projecting members may be in the form of spindles instead of pins, if desired.
• a rotary machine according to the invention is not limited in application to internal combustion engines and may be applied to air compressors, hydraulic motors, steam engines, pumps and like devices.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Compressors, Vaccum Pumps And Other Relevant Systems (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=3691007

Family Applications (1)

Country Status (2)

Families Citing this family (4)

Family Cites Families (6)

• 1986
  • 1986-04-15 WO PCT/AU1986/000098 patent/WO1986006134A1/en unknown
  • 1986-04-15 EP EP19860903113 patent/EP0217949A1/de not_active Withdrawn

Non-Patent Citations (1)

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