EP3587732A1

EP3587732A1 - Positive displacement machine with oscillating and rotary pistons

Info

Publication number: EP3587732A1
Application number: EP18180423.8A
Authority: EP
Inventors: Piergiorgio Cazzin
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-06-28
Filing date: 2018-06-28
Publication date: 2020-01-01

Abstract

Positive displacement machine with oscillating and rotary pistons characterized by comprising- a fixed stator (2)- a rotor (12) coaxial to the stator- at least one intake port (48) housed in the stator and which puts the rotor in communication with the external environment- at least one exhaust port (46) housed in the stator and which puts the rotor in communication with the external environment- a crankshaft (36) coaxial to the stator and to the rotor- bearings integral with the rotor (12) and supporting the crankshaft (36)- bearings integral with the stator (2) and supporting the rotor (12)- an inverter of the rotation motion which engages the crankshaft (36) and the rotor (12) to have opposite and synchronous rotations- at least two shaped inserts (17), integral with the rotor that delimit a chamber (20)- at least one oscillating body (22) inside the chamber (20), this oscillating body (22) having one of the end in correspondence of the first shaped insert (17) of the rotor (12), and being integral with a pin (24) which in turn is articulated to the annular flanges (14) of the rotor (12) and having furthermore articulated, in a median position, by means of a gudgeon pin (26) at the small end (28) of a connecting rod (30) whose the big end (32) is articulated to the crank (34) of the crankshaft (36).

Description

The present invention relates to a positive displacement machine with oscillating and rotary pistons.
Positive displacement machines are known, constituted by a fixed element (called stator) and one or more movable organs that together make, with the stator, cavities (or chambers) whose volume varies periodically with the system's general motion.
These variable volume chambers are placed in communication through appropriate conduits with two environments containing a fluid at different pressures. If the fluid gives energy to the movable organs of the mechanism, this mechanism constitutes an engine. If vice versa the movable organs of the mechanism give energy to the fluid, the mechanism is a fluid machine. (as a pump, a compressor, a fan or a vacuum pump).
DE 22 34 950 A1 describes a rotary piston machine, preferably adapted as an internal combustion engine. In this document, the element 5 of Figures 1 and 2 is a fixed pin installed integrally with the stator with eccentricity and orientation fixed with respect to the rotor center of rotation.
US 3 373 723 A refers to an internal combustion engine having a plurality of oscillating pistons. In this document there is no crankshaft but a "fixed" shaft 26 blocked by the flanges 14 and 20 of the stator and from these prevented from rotation therefrom.
US 3 320 936 A describes a rotary engine with three oscillating bodies. In this document the connecting rods' system is composed of a single crank 80 on which a body is articulated to three equiangolate radial spokes to 120°, on each of which is articulated one of the three connecting rods which in turn are articulated to one of the three oscillating organs.
US 1 715 490 A discloses a steam driven rotary engine in which a crankshaft is not provided.
The object of the present invention is to make a positive displacement machine which has a high efficiency both as endothermic and not endothermic engine and as compressor, pump etc.
This object is achieved according to the invention with a positive displacement machine with oscillating and rotary pistons as described in claim 1.
The present invention is hereinafter further clarified with reference to the enclosed drawings in which:

Figure 1: shows in cross section the machine according to the invention
Figure 2: shows it in longitudinal section
Figure 3: shows the stator and rotor according to section III-III of Figure 1,
Figure 4: shows the stator, the rotor and the system of the connecting rods and cranks according to section IV-IV of Figure 1,
Figures 5-17: represent a complete four-phase cycle of the machine,
Figures 18-30: represent two complete two-phase cycles,
Figure 31-32: represent the geometry of the connecting rods and cranks system.

As can be seen from Figures 1 and 2, the positive displacement machine with oscillating and rotary pistons according to the invention consists substantially of a fixed stator 2, a rotor 12 and a crankshaft 36 both concentric to the stator 2. The fixed stator 2 is in turn formed by a cylindrical body 4 to which two flanges 6 are applied laterally.
The flanges 6 are connected to the cylindrical body 4 by means of the screw rods 10.
Inside the stator 2 is located in concentric position the rotor 12 formed by two symmetrical parts and precisely two annular flanges 14 reinforced by two discs 16.
Inside the two annular flanges 14 four shaped inserts 17 are fixed which divide the inner space of the rotor 12 into four zones (or chambers) 20 inside which are housed four oscillating bodies 22 fixed to four pins 24 which in turn they are articulated to the annular flanges 14 of the rotor 12 (figure 3).
Each oscillating bodies 22 is furthermore articulated, in a median position, by means of a gudgeon pin 26 at the small end 28 of a connecting rod 30 whose the big end 32 is articulated to the crank 34 of the crankshaft 36 (Figure 4).
The crankshaft 36 continues with a shaft extension 38 which is integral with a gear 40 that meshes by means of one or more idler gear 42 a gear 44 integral with the rotor.
The gears 40 and 44 have the same constructive characteristics and specular shape and share the same gear module with the idler gears 42. This assembly of gears is contained by the box 62 integral with the stator 2. The idler gears 42 turn around they own axis which is constrained to the box (62) by means of bearings.
In this way, the rotation in one direction of the crankshaft 36 corresponds to a rotation in the opposite direction of the rotor 12.
Since the shaped inserts 17, the oscillating bodies 22 and the annular flanges 14 of the rotor 12 have the contiguous profiles and are made gas tight between them, it follows that, during operation, the free ends of each oscillating bodies 22 slide tightly and are gas-tight on the cylindrical surfaces of the shaped inserts 17, while the side plane faces of the oscillating bodies 22 slide tightly and are gas tight on the inner walls of the annular flanges 14 of the rotor 12.
In the cylindrical body 4 of the stator 2 (in the configuration shown in Figures 1 and 2) there are an exhaust port 46, an intake port 48, a cooling fluid inlet 50 and a cooling fluid outlet 52. The cooling fluid flows inside the cooling jacket 51 formed inside the stator 4. In the case where the machine is used as an engine, there is also a threaded seat 54 provided with a spark plug 56.
The number of ports and seats provided in the body of the stator 4, as will be seen below, may vary according to the number of phases of the cycle, type of cycle and practical use of the machine.
The space indicated in Figure 1 between the cavity of the stator 4, which houses the electrodes of the spark plug 56, the oscillating body 22 positioned at the second (TDC) top dead center and the shaped insert 17, constitutes the combustion chamber (or clearance volume) 58.
The rotor is connected to a drive shaft 60 constituting the power take-off of the machine, which shaft 60 is contained by the box 64 integral with the stator 2.
The operation of the machine according to the invention is as follows with reference to Figures 5-17 in which a four phases cycle is shown.
For greater clarity, we will analyze the complete rotation of a single mechanical assembly consisting of an oscillating body 22, a connecting rod 30 and a crank 34 and two shaped inserts 17.
In particular:

the clockwise rotation of the rotor 12 drags the pin 24 and the gudgeon pin 26, which are integral with the oscillating body 22, in clockwise rotation,
the anticlockwise rotation (synchronous with respect to the rotation of the rotor) of the crankshaft 36 drags the crank 34 in an anticlockwise rotation.

The connecting rod 30 has the small end 28 articulated to the gudgeon pin 26 of the oscillating body 22 and the large end 32 articulated to the crank 34 of the crankshaft 36.
Therefore, the crank 34, in an eccentric anticlockwise rotary motion, forces (via the connecting rod 30) the oscillating body 22 to perform, during rotation, an reciprocating rotary movement between a TDC (top dead center) and an BDC (bottom dead center) and vice versa.
This rotary oscillation has the pin 24 as the center of rotation and it is cyclic ie, the transition from the TDC (top dead center) to the BDC (bottom dead center) happens in the firsts 90 ° of rotation of the rotor 12 (figs 5-8), and vice versa the transition from the BDC to the TDC happens in the successive rotation of 90° of the rotor 12 according to a cycle that is repeated continuously (figs 8-11). Therefore the complete oscillation of the oscillating body 22 happens every 180 ° of rotation of the rotor 12 (Figures 5-11), therefore every oscillating body will have two positions at TDC (top dead center) and two positions at BDC (bottom dead center) every turn of the rotor 12.

More specifically:

During the suction (intake) phase (Fig. 5-8) the air enters the machine through the intake port 48, filling the chamber 20 whose volume cyclically increases from a minimum value to TDC (top dead center) (Fig. 5) to a maximum value to BDC (bottom dead center) (fig 8).
This phase, excluding of the friction of moving parts, does not absorb energy from the system.
During the compression phase (Figures 8-11) the air, previously aspirated, is compressed in the chamber 20 whose volume cyclically decreases from a maximum value BDC (bottom dead center) (Fig. 8) to a minimum value TDC (top dead center) (Fig. 11) and in this way the air, forced in a environment that decreases in volume, increases in pressure and temperature.
The ratio between the initial (maximum) and final (minimum) chamber volume is called the compression ratio; the final volume of the chamber is called the combustion chamber (or clearance volume) 58.
This phase, excluding of the friction of moving parts, absorbs energy from the system.
In the subsequent burst/expansion phase (Figures 11-14), a fuel charge is dosed in the air previously compressed to forming a fuel-air mixture that burst with the spark of ignition spark plug 56, in turn commanded by a device suitably synchronized with the general motion of the system.
This combustion generates heat which further raises the temperature and pressure of the ignited mixture. The pressure applied to the walls of the chamber 20 causes the expansion of the chamber itself (expansion which can occur only during the rotation of the rotor 12) whose volume increases from a minimum value TDC (in which the pressure is maximum) (Fig. 11) to a maximum value BDC (where the pressure is minimal) (Fig. 14).
This phase, excluding of the friction of moving parts, provides energy to the system.
In the subsequent and final exhaust phase (Figs 14-17) the residual combustion products through the exhaust port 46 are expelled from the chamber whose volume cyclically decreases from a maximum value BDC fig.14) to a minimum value TDC (fig 17).
This phase, excluding of the friction of moving parts, does not absorb energy from the system.
Since at each rotation of 360° of the rotor 12 corresponds to a contrary rotation of 360° of the crankshaft 36, an angle of 720 ° is achieved between the two members for each revolution of the axis of the rotor 12.
Considering that a reciprocating motion machine achieves a useful phase every 180 ° of rotation of the axis, the present machine produces for each oscillating body 22, four useful phases (720 ° /180 ° = 4) at each revolution of the rotor axis 12.
It follows that the machine described here produces a phase every 90 ° of rotation of the rotor axis. For example, each oscillating body can perform the intake / compression / burst / exhaust cycle typical of a 4-stroke endothermic engine at each revolution of the rotor as indicated in Figures 5-17.
By changing the configuration of the stator 4, each oscillating body can realize the two-stroke intake / compression cycle, typical of a fluid machine, twice with each revolution of the rotor12 as indicated in Figures 18 - 30.
the machine can be used as a engine by adopting a cycle with the four phases described above because the burst / expansion phase provides the system with the energy necessary to overcome the friction generated by the moving parts as well as the passive forces that develop during air compression phase in a balance sheet that remains positive even after deducting these losses. (Fig. 5-17).
In a variant embodiment, the machine can be used as an operating machine by adopting a two-stroke cycle, such as the intake phase and the compression phase, typical of a fluid machine (as a compressor or as a pump, etc.).
In this case the energy required to overcome the frictions as well as the passive forces that develop during the phases must be provided by an external source. (Figg.18-30).

Claims

Positive displacement machine with oscillating and rotary pistons characterized by comprising
- a fixed stator (2)

- a rotor (12) coaxial to the stator

- at least one intake port (48) housed in the stator and which puts the rotor in communication with the external environment

- at least one exhaust port (46) housed in the stator and which puts the rotor in communication with the external environment

- a crankshaft (36) coaxial to the stator and to the rotor

- bearings integral with the rotor (12) and supporting the crankshaft (36)

- bearings integral with the stator (2) and supporting the rotor (12)

- an inverter of the rotation motion which engages the crankshaft (36) and the rotor (12) to have opposite and synchronous rotations

- at least two shaped inserts (17), integral with the rotor that delimit a chamber (20)

- at least one oscillating body (22) inside the chamber (20), this oscillating body (22) having one of the end in correspondence of the first shaped insert (17) of the rotor (12), and being integral with a pin (24) which in turn is articulated to the annular flanges (14) of the rotor (12) and having furthermore articulated, in a median position, by means of a gudgeon pin (26) at the small end (28) of a connecting rod (30) whose the big end (32) is articulated to the crank (34) of the crankshaft (36).
A machine according to claim 1, characterized in that the rotation motion inverter consists of a gear (40) integral with the crankshaft (36) a gear (44) integral with the rotor (12), at least one idler gear (42), integral with the box (62) that turns around its own axis and meshes the gears (40) and (44) to rotate with reverse and synchronous rotative motion.
A machine according to claim 1 characterized in that it further comprises a spark plug of ignition.
A machine according to claim 2 characterized in that the gears (40) and (44) have the same constructive characteristics and specular shape and share the same teeth type with the idler gear (42).
A machine according to claim 1, characterized in that, at each rotation of the rotor (12) of 90 °, a space (58) is formed between the cavity of the stator (4) which houses the electrodes of the spark plug (56), the oscillating body (22) in rotation when it reaches the second top dead center (TDC) and the shaped insert (17), said space constituting the combustion chamber and having two between the walls containing it, one in the stator (4) and one in the shaped insert (17) of the rotor (12) in the opposite positions.
A machine according to claim 1 characterized in that it comprises at least a couple of connecting rod (30) - crank (34) for each individual oscillating body (22).