Classifications

• • 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
  • F02B75/32—Engines characterised by connections between pistons and main shafts and not specific to preceding main groups
• • 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, not specific to groups F01B1/00 - F01B7/00
  • F01B9/02—Reciprocating-piston machines or engines characterised by connections between pistons and main shafts, not specific to groups F01B1/00 - F01B7/00 with crankshaft
  • F01B9/026—Rigid connections between piston and rod; Oscillating pistons

Definitions

• the present invention relates to a device which may be used in place of the classical crank mechanism, in order to convert a reciprocating linear motion into a rotational motion, and vice versa.
• the present device may be applied to reciprocating volumetric internal combustion engines, or to compressors, even if it is not limited to such applications.
• the conventional crank mechanism of an internal combustion engine has several drawbacks .
• the classical crank mechanism has in this connection certain limits, because it generally comprises a connecting rod which translates and oscillates at the same time during its motion, thereby preventing to go beyond certain limits of the stroke, due to space (obstruction) problems.
• An object of the present invention is to realize a device suited to convert a rectilinear reciprocating motion into a rotational motion, and vice versa, based on a totally different principle, according to which the end of the connecting rod, instead of performing a rotational motion, will move along a straight line.
• a further object of the invention - when applied to internal combustion engines -, is to realize a device which eliminates the above mentioned disadvantages of the known art .
• the device will allow the piston to more effectively transmit to the driving shaft the force generated inside the combustion chamber, by generating, in each cycle, a diagram of the moment of the engine, which is much more advantageous. Since the engine power is instantaneously given by the product of the angular velocity and the torque, it can be deduced that the overall power will increase.
• An additional object of the present invention is to use, in order to realize the device for converting the linear reciprocating motion into rotational motion, members or components which perform rotational motions and which are naturally balanced due to their shapes. Therefore, they will not require the addition of counterweights. Even if the rotation occurs at a very high rpm value, the driving shaft vibrations are extremely reduced and the motion will be very smooth.
• the present invention attains the above mentioned objects, by means of a device for converting a rectilinear reciprocating motion into a rotational motion, or vice versa, comprising:
• a rotor which includes the connecting rod rotation axis, and wherefrom/whereto power may be drawn/transmitted, directly or indirectly, for example by means of a synchronization shaft;
• the pin of the connecting rod is connected by a rod or bar to the piston of the cylinder.
• the connecting rod pin will perform a rectilinear, or almost rectilinear, reciprocating motion. In case the motion is rectilinear, the rod or bar must not be necessarily connected to the piston in the form of an articulated joint, but may be rigidly connected thereto.
• said rod or bar for the connection to the movable member may also be called “plunger” .
• the movable member is a piston which performs a reciprocating linear motion. It obviously follows that the piston stroke may be much larger than the piston diameter. This will allow to choose (select) the size of the device components in relation to the force acting on the piston, which will be lower in case of swept volumes having small cylinder bores and large strokes. Thus, the engine weight will be reduced.
• Said means for imposing to the connecting rod and to the rotor the above mentioned relative movements preferably are embodied by gearwheels.
• the connecting rod By mounting the connecting rod on a crown wheel, according to claim 2, wherein the diameter of the pitch circle of the crown wheel or planet wheel is equal to half the diameter of the pitch circle of the "fellow" wheel (ring gear with internal or external toothing), it is possible to obtain a rotation by an angle 2a of the crown or planet wheel around its own axis. Simultaneously, the rotor, and the planet wheel center (or center of connecting rod), will have moved by an angle a in the opposite direction, around the rotor center, the latter being the rotating member which for instance (in the application concerning internal combustion engines) is directly or indirectly connected to the engine driving shaft.
• the connecting rod pin will move along an almost rectilinear path, and said path is perfectly rectilinear provided that - according to claim 6 - , the centers of the two engaging wheels (planet wheel and fellow wheel or ring gear) define a segment, equal to the radius of the orbit of the rotation center of the planet wheel, which exactly corresponds to the distance between the connecting rod pin, and the center of the planet wheel (crown wheel).
• the device implementation by means of gearwheels may also make use of a "fellow wheel” or ring gear with an external -instead of internal- toothing, as indicated in claim 3 and claim 4. In both cases, it is of primary importance that the diameter of the fellow wheel toothing (the pitch circle diameter) be always equal to twice the diameter of the planet wheel (planet wheel toothing).
• Fig. 1 is a schematic drawing of the principle of operation of the device of the present invention, as compared with the classical crank mechanism;
• Fig. 2 is a view of the assembly formed by the ring gear, or fellow wheel, with internal toothing, by the planet wheel which is integral with the connecting rod, and by the connecting rod itself, in the position corresponding to the top dead center (TDC) of the movable member having a reciprocating rectilinear motion, this drawing showing the use of two gearwheels for the device implementation;
• Fig. 3 is a view of the assembly shown in Fig. 2, showing - in an intermediate position of the planet wheel - how the conditions of the principle of operation regarding the angles of relative rotation, are satisfied, and how the connecting rod pin moves along a straight line (X-axis);
• Fig. 4 illustrates the sequence of movements of the planet wheel (crown wheel) according to four different positions
• Fig. 5 shows an application according to which a disk is used instead of the connecting rod, in order to provide thereon a plurality of pins whose loci correspond to "reciprocating" rectilinear trajectories, out of phase with respect to each other;
• Fig. 6a is a view of a first possible embodiment of the device according to the present invention, which is especially suited for relatively small strokes of the movable member performing a rectilinear reciprocating motion;
• Fig. 6b is an exploded perspective view of the embodiment of Fig. 6a;
• Fig. 7 is a sectional view of a second possible embodiment of the device according to the present invention, particularly suited for larger strokes of the piston inside the cylinder, and in which the fellow wheel, or ring gear, has an external toothing.
• gearwheels may be employed, which allow to realize during the motion - by their gear ratios - the constraint according to which, when segment OC covers an angle b around its center 0, segment CB covers an angle which is twice that angle, in the opposite direction of rotation.
• Fig. 2 schematically shows the arrangement of the essential members or components whose relative movement is used to generate the desired reciprocating motion. In this figure, by comparison with the right side of Fig.
• the planet wheel 3, which engages with the ring gear 1, will also rotate around its axis 02, due to the rotation of its center 02 around 01, and said rotation of the planet wheel will correspond to an angle 2a (since the gear transmission ratio between these two members is 2:1) and will occur in the opposite direction (anticlockwise).
• the connecting rod 4, which - as mentioned above - is integral with the planet wheel 3, will rotate by the same angle as the latter, thereby shifting its point 03 once again along the axis X of Fig. 2.
• Fig. 4 there are shown some of the infinite number of positions the system may assume during the rotation, in order to better illustrate the dynamics of the movement, and the same figure also shows the two points S and I which correspond to the end-of-stroke positions.
• a disk 6 which is also integral with the planet wheel, is used instead of the connecting rod 4 of Fig. 2, as shown in Fig. 5, by fixing on the disk a generic point 04 rotated by a certain angle 2a with respect to 02 and located on the same circumference as 03, the said point will move - during the rotation - along a different rectilinear trajectory, which is tilted by an angle a with respect to the first trajectory (X-axis).
• a plurality of movable members with rectilinear reciprocating motion and out of phase one with respect to the other by arbitrary angles may be connected to the disk 6 and around the same.
• Fig. 6a shows a cross-section of a first embodiment of the device, selected among several possible embodiments, and which is preferably used when the stroke of the piston is limited.
• Fig. 6b shows the same embodiment of fig. 6a, with some slight variants, and according to a perspective exploded view.
• ring gear 1 is received inside the block or frame 7 provided with cover 8.
• the planet wheel 3 of radius R/2 is actually introduced inside the rotor 30, and the latter, as best shown in Fig. 6b, is provided with a cylindrical seat 9.
• the toothing of the planet wheel 3 denoted by numeral 5 , engages the fellow wheel or ring gear 1 with internal toothing of double radius (equal to R) with respect to that of the planet wheel 3.
• the cylindrical seat 9 has a discontinuity, that is, it does not extend along the whole longitudinal extension of the rotor 30, so that the toothing 5 of the planet wheel 3 can engage the fellow wheel or ring gear 1 whose toothing is denoted by 2.
• the planet wheel 3 of radius R/2 has an integral hub 11 lodged inside an extension of rotor 30.
• the hub 11 is received inside bearings or a bearing brass (hatched portion).
• the planet wheel 3 and the rotor 30 are supported by bearings or a bearing brass respectively indicated by 12 and 13.
• the portion of the rotor 30 indicated by numeral 10, adjacent to the wall 8, may form a gearwheel in the variant of Fig. 6b, in which said gearwheel 14 remains uncovered (the upper wall 7 of Fig. 6a is omitted) and may be used for the synchronization of several devices of the same kind as that shown in Fig. 6b, through a synchronization shaft (not shown) which draws and collects the power from the plurality of devices.
• a further modification with respect to Fig. 6a is that (see Fig.
• the device of the invention is "duplicated", in the sense that the further planet wheel 3' may be introduced inside a second rotor 30 in order to increase the resistance of the mechanism.
• the driving shaft is denoted by numeral 16 and is integral with the rotor 30; it projects out of wall 8. It can also be observed that the driving shaft 16 is supported by a bearing brass 17.
• the axes 18, 19, 20 respectively indicate the axes of components 16, 3, 15. It is appropriate to recall and stress the fact that in case more than one mechanism are assembled together in the same engine, it is necessary to synchronize these mechanisms . This may be achieved as follows:
• gear wheel 14 is rigidly connected, e.g. keyed, or directly formed on each rotor 30, and each of said gear wheels has the same pitch circle diameter as the other ones (see for instance in Fig. 6a the region between the ring wheel 1 and the cover 8; portion 10 of rotor 30);
• a transversal shaft is added to the assembly, which has a number of gearwheels corresponding to the number of devices (mechanisms), wherein each of the gearwheels of the transversal shaft engages a corresponding gearwheel 14.
• the additional shaft besides the function of synchronization, also accomplishes the task of collecting the work done by each mechanism, it will provide a single power take-off of the engine or machine at the output of its frame.
• Fig. 7 shows the following essential elements: - a support 21 of the mechanism, receiving therein two shafts 22, 23 freely movable inside a respective bearing brass (hatched);

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Transmission Devices (AREA)
• Compressor (AREA)
• Automatic Cycles, And Cycles In General (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=11406972

Family Applications (1)

Country Status (9)

Families Citing this family (9)

Family Cites Families (5)

• 1999
  • 1999-09-24 IT IT1999RM000593A patent/IT1309063B1/it active
• 2000
  • 2000-08-09 EA EA200200402A patent/EA003724B1/ru not_active IP Right Cessation
  • 2000-08-09 WO PCT/IT2000/000337 patent/WO2001021947A1/en not_active Ceased
  • 2000-08-09 JP JP2001525088A patent/JP2003510528A/ja active Pending
  • 2000-08-09 AU AU67244/00A patent/AU6724400A/en not_active Abandoned
  • 2000-08-09 CA CA002385112A patent/CA2385112A1/en not_active Abandoned
  • 2000-08-09 BR BR0014228-0A patent/BR0014228A/pt not_active Application Discontinuation
  • 2000-08-09 CN CN00813224.0A patent/CN1376237A/zh active Pending
  • 2000-08-09 EP EP00954896A patent/EP1214507A1/de not_active Withdrawn

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events