CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 63/116,961, filed November 23, 2020.

TECHNICAL FIELD

[0002] The present disclosure relates to the field of internal combustion engines, and may more particularly relate to oscillating systems using one or more engines and configured to transform linear reciprocating motion to energy of another form.

BACKGROUND

[0003] Internal combustion engines are known. Some engine configurations include single or multi-cylinder piston engines, opposed-piston engines, and rotary engines, for example. The most common types of piston engines are two-stroke engines and four-stroke engines. In addition, a free piston engine may include a piston that moves without being constrained by a crankshaft. A linear reciprocating engine may have a piston configured to slide along a linear path with a piston rod that reciprocates along the linear path. Systems that employ engines may have great potential for generating power by converting chemical energy of fuels into mechanical motion, or energy of another form. However, improvements are desired in systems that use engines, and components thereof, such as energy transformation mechanisms.

SUMMARY

[0004] Some embodiments may relate to a system including an internal combustion engine, such as a linear reciprocating engine. An engine may include a piston configured to linearly reciprocate along an axis in a cylinder. A piston rod may be connected to the piston. The piston rod may be configured to linearly reciprocate along the axis. A power take off (PTO) may be configured to transform linear reciprocating motion of the piston rod to energy of another form.

[0005] Advantages and effects of the embodiments of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein certain embodiments are set forth by way of illustration and example. It is to be understood that both the foregoing general description and the following detailed description merely provide examples, are explanatory only, and are not restrictive of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Fig. 1 is diagrammatic representation of an oscillating system, consistent with embodiments of the present disclosure;

Figs. 2A-2D are diagrammatic representations of a system at various operational states, consistent with embodiments of the present disclosure;

Figs. 3A-3B are diagrammatic representations of a system using a double-sided piston, consistent with embodiments of the present disclosure;

Figs. 4A-4D are diagrammatic representations of a system using a double-sided piston and a pump, consistent with embodiments of the present disclosure;

Figs. 5A-5C are overall views of a system that may be useful for power generation, consistent with embodiments of the present disclosure;

Figs. 6A-6E are diagrammatic representations of a system at various operational states, consistent with embodiments of the present disclosure; and

Figs. 7A-7C are diagrammatic representations of a pump and inlet unit, consistent with embodiments of the present disclosure.

DETAILED DESCRIPTION

[0007] Reference will now be made in detail to examples of embodiments, which are illustrated in the accompanying drawings. The following descriptions refer to the accompanying drawings in which the same numbers in different drawings may represent the same or similar elements unless otherwise represented. The implementations set forth in the following description of embodiments do not represent all implementations consistent with the invention. Instead, they are merely examples of systems, apparatuses, and methods consistent with aspects related to the invention as may be recited in the claims. Relative dimensions of elements in drawings may be exaggerated for clarity. [0008] An internal combustion engine may be configured to output power by having a piston rod attached to a piston reciprocate in a linear path. The piston rod may be configured to generate pushing or pulling forces. Some engines may be configured such that the piston rod generates both pushing and pulling forces (e.g., using a double-sided piston).

[0009] To harness such forces, a power take off (PTO) may be provided that is configured to transform linear reciprocating motion of the piston rod to energy of another form. For example, the PTO may include a mechanism that transforms linear motion to rotative motion. The rotative motion may be fed to another component, such as an alternator, a flywheel, a pump, etc. The other component (e.g., alternator) may be configured to generate electrical energy with each power stroke of the engine by applying resistance.

[0010] A system may involve one or more engines generating pushing or pulling forces. The system may be an oscillating system. For example, components of an engine (e.g., a piston) may move back and forth (i.e., reciprocate). The system may be configured to use oscillating motion of the engine and apply it to other components in the system (e.g., to pump air or to generate electricity). The oscillating motion of the engine may be balanced by oscillating motion of other components, such as another engine, a mover, or a pump. The system may be balanced by having a first component configured to oscillate in a first manner and a second component configured to oscillate in a second manner. For example, a first engine may be configured such that its piston is at a top position while a piston of a second engine is at a bottom position. In some embodiments, a double-sided piston of an engine may be used and it may be balanced against a doubled-sided piston of an air pump. The air pump may act as a turbocharger to supply charged air to the engine. As the engine reciprocates, motion of the piston may be used to drive the air pump. In turn, the air compressed by the air pump may be input to the engine, allowing greater volume of air and mass of fuel to be delivered to the combustion chambers of the engine, and enhancing power generation.

[0011] Meanwhile, motion of oscillating components may be captured and converted to another form of energy. Oscillating motion of components in the system may be harnessed so as to transform between mechanical motion (e.g., linear reciprocating motion of a piston rod) and energy of another form (e.g., electrical energy). In some embodiments, the energy of the other form may be stored (e.g., in a battery, capacitor, or any energy storage device). A PTO may be configured to harness oscillating motion of components in the system. For example, a rotative body (e.g., a disc, a lever, or any pivoting member) may be attached to an end of a piston rod. The rotative body may be configured to rotate in a first rotative direction (e.g., clockwise) as the piston rod moves in a first linear direction (e.g., up). A piston connected to the piston rod may move in a power stroke from a combustion point (e.g., one end of a cylinder) to a position of maximum travel (e.g., an opposite end of the cylinder). During the power stroke, the piston rod may move in the first linear direction and the rotative body may rotate in the first rotative direction.

[0012] The PTO may be configured to harness motion of components of the system in various directions. For example, the rotative body may be configured to rotate in a second rotative direction that is different from the first rotative direction. The second rotative direction may be opposite the first rotative direction. The rotative body may be configured to rotate in the second rotative direction (e.g., counter-clockwise) as the piston rod moves in a second linear direction (e.g., down). The system may be configured to harness useful work from all moving parts (e.g., the piston assembly, the rotative body, and the pump).

[0013] The PTO may be configured to move in segments (e.g., a segment of a circular path) as components of the system move in various directions. For example, the rotative body of the actuator may be configured to rotate in the first direction for a predetermined amount (e.g., a time or distance) for the power stroke of the first engine. The rotative body may be configured to rotate in the second direction for a predetermined amount for a return stroke of the first engine. The return stroke of the first engine may correspond to movement of another component (e.g., a power stroke of a second engine).

[0014] The PTO may be configured to capture work from one or more engines during portions of movement of the actuator through its movement range. The PTO may be configured to selectively capture work from one or more engines. The PTO may be configured to capture work from one or more engines only during portions where respective ones of the one or more engines are powered (e.g., during a power stroke). For example, the PTO may be configured to capture work from a first engine while its piston is in a power stroke, and this may correspond to movement in a first segment. The PTO may be configured to capture work from a second engine while its piston is in a power stroke, and this may correspond to movement in a second segment. Directions of movement of the actuator in the different power strokes may be opposite. The PTO may be configured to selectively engage a power transfer mechanism. Power may be continuously harvested as the two engines reciprocate.

[0015] The PTO may comprise a clutch. The clutch may be configured to capture work while an engine of the one or more engines is powered, and to allow freewheeling while an engine of the one or more engines is not powered. A clutch may connect the PTO, which may be rotating under power from the engine, to another component, such as a flywheel, such that torque is transferred to the other component when the clutch is engaged. When the clutch is not engaged, the PTO may be disconnected from the other component. Thus, if the PTO is no longer powered by the engine, or if the PTO rotates in a reverse direction, it may rotate independently from the other component. In some embodiments, a plurality of clutches may be provided.

[0016] The rotative body of the PTO may be configured to rotate in the first direction during the power stroke of the first engine and may rotate in the second direction during the power stroke of the second engine. The rotative body of the PTO may be configured to rotate in the second direction for a predetermined amount (e.g., a time or distance) for the power stroke of the second engine. In some embodiments, the rotative body may be configured to rotate in the second direction for a stroke of some other component (e.g., a stroke of an air pump).

[0017] The PTO may be configured to rotate back and forth in segments as the engine reciprocates in a linear path. The PTO may transform segments of rotative motion into other forms of energy, such as electrical energy. For example, an alternator may transform segments of rotative motion of the rotative body to electrical energy.

[0018] The PTO may include a linkage configured to couple the rotative body to a piston rod. The linkage may include a first linkage configured to couple the rotative body to a first piston rod of a first engine. The linkage may also include a second linkage. The second linkage may be configured to couple the rotative body to a second piston rod of a second engine. In some embodiments, the second linkage may be configured to couple the rotative body to a rod of another component, such as an air pump. [0019] The PTO may include a mechanism to transform linear motion to rotative motion, or to transform motion of a piston rod to output of some other form. The mechanism may include a ring gear or other types of mechanical systems. Linear motion of the piston and piston rod may be transformed into rotative motion that turns a rotative member. The rotative member may be used to harness work of the engine. The rotative member may drive a wheel, or may power a generator, for example.

[0020] A linear reciprocating engine may include a free piston and may be well-suited to accommodate different types of fuels, combustion points, compression ratios, and other operational conditions. A linear reciprocating engine may have a variable combustion point. Furthermore, a linear reciprocating engine may be configured to use spontaneous combustion. For example, a linear reciprocating engine may be configured to use homogeneous charge compression ignition (HCCI). Fuel may be injected into a cylinder at an optimal point during a stroke, and an air-fuel mixture may be formed in a combustion chamber. The air-fuel mixture may spontaneously combust when volume (or another parameter) of the combustion chamber reaches a certain point. Systems using a linear reciprocating engine may be useful because the engine may have a variable combustion point and may allow for flexible energy extraction. Spontaneous combustion may enhance power generation characteristics of the engine by, for example, reducing or eliminating a flame front in a combustion chamber. Rather than having a flame front propagate throughout the combustion chamber, spontaneous combustion may allow combustion to occur more uniformly throughout the entire combustion chamber (e.g., homogenously).

[0021] According to some embodiments of the disclosure, a system employing an engine may be provided that is compact and lightweight. The engine may achieve high efficiency and reduced environmental contamination. The engine may reduce or eliminate the need to provide a lubricant, such as oil. The engine may achieve a high power-to-weight ratio. The system may efficiently extract energy from the engine.

[0022] As used herein, unless specifically stated otherwise, the term “or” encompasses all possible combinations, except where infeasible. For example, if it is stated that a component includes A or B, then, unless specifically stated otherwise or infeasible, the component may include A, or B, or A and B. As a second example, if it is stated that a component includes A, B, or C, then, unless specifically stated otherwise or infeasible, the component may include A, or B, or C, or A and B, or A and C, or B and C, or A and B and C. Furthermore, the phrase “one of’ shall be interpreted broadly such that “one of A and B” means one of A or one of B. The phrase “one of A and B” does not exclude a combination of one of A and one of B. Phrases such as “one of A or B” shall similarly be interpreted broadly.

[0023] Fig. 1 illustrates an oscillating system 100 consistent with embodiments of the present disclosure. System 100 may include a first oscillator 110 and a second oscillator 120. System 100 may also include a power take off (PTO) 130. Oscillating system 100 may include a linear engine system. Oscillators may include combustion chambers. A combustion chamber may include any enclosed volume configured for combustion to take place therein. For example, a combustion chamber may include a volume bounded by a cylinder, piston, and a cylinder or engine head. The combustion chamber may be part of an internal combustion engine. The combustion chamber may include a swept volume between a cylinder head and a moving face of a piston. As the piston reciprocates, the volume of the combustion chamber may change, and the combustion chamber may achieve a certain compression ratio. In some embodiments, combustion within a combustion chamber may be triggered by an igniter, such as a spark plug. In some embodiments, combustion within a combustion chamber may occur spontaneously (e.g., by HCCI).

[0024] A linear engine system may include a first combustion chamber and a first piston assembly within the first combustion chamber. The linear engine system may also include a second combustion chamber and a second piston assembly within the second combustion chamber. A combustion chamber may include a cylinder having a slidable piston enclosed therein. The piston may reciprocate linearly between different positions in the cylinder. The combustion chamber may include an engine. For example, the first piston assembly within the first combustion chamber may be configured to reciprocate between a first end of the first combustion chamber and a second end of the first combustion chamber.

[0025] A piston rod may be attached to a piston and may be used to transfer energy of the moving piston outside the combustion chamber. The first piston assembly may have at least one first piston rod connected thereto. The at least one first piston rod may extend to locations outside the combustion chamber. The at least one first piston rod may also extend within the combustion chamber. For example, the at least one first piston rod may extend within the first combustion chamber and exit the first combustion chamber on at least one of the first end and the second end. The at least one first piston rod may be configured to reciprocate along a first linear path. The first piston assembly may also be configured to reciprocate along the first linear path. Similarly, a second piston assembly may have at least one second piston rod connected thereto and may also reciprocate along a linear path.

[0026] The linear engine system may also include a power take off (PTO). The PTO may include a device configured to transfer mechanical power of a piece of equipment (e.g., an engine) to another piece of equipment. The PTO may include a mechanism that provides output movement when input movement is supplied thereto. In some embodiments, the PTO may include a device seated on a flywheel housing configured to transfer power from a drive component (e.g., a piston rod of an engine) to a secondary application (e.g., an implement, such as a generator). The PTO may drive a secondary shaft that may in turn drive other equipment, such as a hydraulic pump, generator, air compressor, pneumatic blower, or vacuum pump.

[0027] As shown in Fig. 1, first oscillator 110 may include a first engine. Second oscillator 120 may include a second engine. First oscillator 110 may include a first combustion chamber and second oscillator 120 may include a second combustion chamber. In some embodiments, second oscillator 120 may include a pump, such as an air pump, compressor, or some other type of oscillating device. In some embodiments, first oscillator 110 or second oscillator 120 may include a double-sided piston. First oscillator 110 or second oscillator 120 may accommodate combustion on either side of the double-sided piston. First oscillator 110 or second oscillator 120 may be configured to have a first power stroke as a piston moves in a first direction along a linear path, and a second power stroke as the piston moves in a second direction along the linear path.

[0028] In some embodiments, the first combustion chamber may have a first combustion side and a second combustion side. Also, the second combustion chamber may have a third combustion side and a fourth combustion side. A first piston assembly may be provided within the first combustion chamber. The first piston assembly may include a piston rod, a piston, and a piston ring. The first piston assembly may be configured to reciprocate between a first end of the first combustion chamber and a second end of the first combustion chamber. The first piston assembly may have a first face for compressing gas on the first combustion side and a second face for compressing gas on the second combustion side. A second piston assembly may be similarly provided in second combustion chamber (e.g., having a third face and a fourth face). In some embodiments, the second piston assembly may have a third face for compressing gas on a first side of a pump and a fourth face for compressing gas on a second side of the pump.

[0029] PTO 130 may be connected to first oscillator 110 and second oscillator 120 via rods 111, 121, respectively. PTO 130 may be configured to rotate as first oscillator 110 and second oscillator 120 reciprocate. A linkage may be provided that allows rods 111, 121 to reciprocate in linear paths while PTO 130 rotates. The linkage may include one or more pivots. A linkage may include a first pivot on a rod (e.g., rod 111) and a second pivot on PTO 130. A linkage may include an extendible portion configured to accommodate a change in distance between the first pivot and the second pivot. Members may be provided that are configured to define the linear paths. For example, linear bearings may be provided. First oscillator 110 may include bushings that surround rod 111. Multiple bushings may be provided at different points along a path of linear travel of rod 111. Second oscillator 120 may include bushings that surround rod 121. Multiple bushings may be provided at different points along a path of linear travel of rod 121. While rods 111, 121 may be constrained to linear paths (e.g., straight up-and-down), linkages may allow movement outside of the linear paths, e.g., side-to-side movement of linkage members connected to ends of rods and to a rotating member of PTO 130.

[0030] First oscillator 110 may be configured to generate a pulling force. For example, in the view of Fig. 1, a combustion chamber may be formed in an upper portion of a cylinder of first oscillator 110, and rod 111 may be configured to move downward during combustion. A piston assembly within an oscillator may have a first face for compressing gas (e.g., air or a fuel-air mixture) on a first combustion side. In some embodiments, first oscillator 110 may be configured to generate a pushing force. For example, a combustion chamber may be formed in a lower portion of a cylinder of first oscillator 110, and rod 111 may be configured to move upward during combustion. PTO 130 may be configured to receive pushing or pulling forces from rod 111.

[0031] Second oscillator 120 may be configured to generate a pulling force or a pushing force that may be transferred via rod 121. Second oscillator may be the same or similar to that of first oscillator 110. PTO 130 may be configured to transfer pushing or pulling forces from rods 111, 121. PTO 130 may transform pushing or pulling forces from rods 111, 121 to torques. PTO 130 may output torques via a rotative body.

[0032] In some embodiments, first oscillator 110 may be configured to generate both pushing and pulling forces. A piston assembly within an oscillator may have a first face for compressing gas on a first combustion side and a second face for compressing gas on a second combustion side. In some embodiments, second oscillator 120 may be configured to use forces transferred from PTO 130. For example, second oscillator 120 may include an air pump configured to receive pushing or pulling forces from rod 121.

[0033] Fig. 2A illustrates a system 100A that may be an example of oscillating system 100. System 100A may include a linear engine system. First oscillator 110 may include a linear reciprocating engine. First oscillator 110 may include a piston 113 configured to reciprocate in a linear path in a cylinder 119. Piston 113 may be a single-sided piston. A combustion chamber 115 may be formed in an upper part of cylinder 119 of first oscillator 110. Rod 111 may be a piston rod connected to piston 113 and configured to reciprocate in a linear path together with piston 113.

[0034] First oscillator 110 may include an air chamber 117. Air chamber 117 may include an intake chamber. Air may be supplied to first oscillator 110 by an air supply (not shown) that may be connected to air chamber 117. Air may be supplied to first oscillator 110 by a channel. Gases may be communicated from air chamber 117 to combustion chamber 115, e.g., by an internal channel. For example, a passage may be provided through piston 113 and through rod 111 that may allow selective gas communication between air chamber 117 and combustion chamber 115. Furthermore, an exhaust opening (not shown) may be provided in cylinder 119. Various other channels may be provided, such as a channel configured to recirculate exhaust gases, a channel configured to capture blowby gases and contain them in a chamber, a channel configured to supply air to second oscillator 120, and others.

[0035] First oscillator 110 may be connected to PTO 130 via a linkage 131. Linkage 131 may be configured to allow rod 111 to reciprocate in a linear path while transferring energy to PTO 130. Linkage 131 may transform linear reciprocating motion of rod 111 to rotative motion to enable a rotative body of PTO 130 to rotate. The rotative body may include a disc. Linkage 131 may be configured by kinematics, for example. Linkage 131 may be configured such that angles, orientation, relative arrangement, etc. of members allows for power transfer through the members in a desired manner. Linkage 131 may be configured to enable efficient power transfer such that a point of peak power generation in first oscillator 110 corresponds to a point of most efficient power transfer to PTO 130. System 100A may be configured such that a connector of linkage 131 is parallel to the linear path of reciprocating motion of rod 111 when first oscillator 110 is at a combustion point. For example, in a case where first oscillator 110 is configured to output a pushing force via rod 111, and chamber 117 is a combustion chamber (as the case may be in some embodiments), a connector of linkage 131 may be approximately parallel to rod 111 at the combustion point (see arrangement as in Fig. 2C). The connector of linkage 131 may remain approximately parallel to rod 111 for a predetermined portion of the stroke (e.g., for 40 to 50% of the length of the stroke as piston 113 moves from a combustion point to a point of maximum travel). In some embodiments, stroke length may be limited by geometry of cylinder 119.

[0036] Linkage 131 may include connecting members. A connecting member may include an eyelet, a pivot, an arm, or any member configured to mechanically connect one or more components and having one or more degrees of freedom.

[0037] Second oscillator 120 may be the same as or similar to first oscillator 110. Second oscillator 120 may be connected to PTO 130 via a linkage 132. Linkage 132 may be the same as or similar to linkage 131.

[0038] In some embodiments, second oscillator 120 may include an air pump. Second oscillator 120 may be configured to receive input (e.g., work) and generate a useful output (e.g., pumping air to supply to first oscillator 110). Linkage 132 may be configured to transfer work to rod 121 to move piston 123, which may be a component of an air pump for compressing air.

[0039] In some embodiments, first oscillator 110 and second oscillator 120 may be configured to generate pulling forces that are transferred to PTO 130 via rods 111, 121. In some embodiments, first oscillator 110 and second oscillator 120 may be configured to generate pushing forces that are transferred to PTO 130 via rods 111, 121. For example, locations of combustion chamber 115 and air chamber 117 in first oscillator 110 may be swapped.

[0040] Depending on whether first oscillator 110 and second oscillator 120 are configured to generate pushing or pulling forces to be transferred to PTO 130 via rods 111, 121, linkages 131, 132 may be configured to enable efficient power transfer. For example, when first oscillator 110 is configured to output a pushing force via rod 111, and chamber 115 is a combustion chamber, a connector of linkage 131 may be approximately parallel to rod 111 at the combustion point that may occur in chamber 115 (e.g., when a critical small volume is reached that may be appropriate for spontaneous combustion) (see Fig. 2A).

[0041] Fig. 2A illustrates system 100A at a position where first oscillator 110 may be at a first point (e.g., a combustion point) while second oscillator 120 is at a second point (e.g., a maximum travel point). Combustion may be about to occur in combustion chamber 115 of first oscillator 110, and combustion in combustion chamber 125 of second oscillator 120 may be completed.

[0042] Fig. 2B illustrates system 100 A at a position where first oscillator 110 and second oscillator 120 may be at mid-points of their respective travel ranges. In first oscillator 110, combustion may be occurring in combustion chamber 115, and in second oscillator 120, piston 123 may be in a compression phase and may be approaching a combustion point.

[0043] Fig. 2C illustrates system 100A at a position where first oscillator 110 may be at a second point (e.g., a maximum travel point) while second oscillator 120 is at a first point (e.g., a combustion point). In Figs. 2A-2C, PTO 130 may rotate in a first rotative direction (e.g., counter-clockwise). PTO 130 may be configured to rotate in a range (e.g., a segment) from the position shown in Fig. 2A to the position shown in Fig. 2C. Following the state shown in Fig. 2C, system 100A may move in a different direction. First oscillator 110 may begin to reciprocate in an opposite direction. Second oscillator 120 also may begin to reciprocate in an opposite direction. PTO 130 may begin to rotate in a second rotative direction different from the first rotative direction (e.g., clockwise). PTO 130 may rotate back and forth, extracting power from either first oscillator 110 or second oscillator 120 with each segment, for example.

[0044] System 100A may be configured to allow PTO 130 to rotate throughout a permissible range, and the permissible range may encompass a range that corresponds to a travel range of first oscillator 110 and second oscillator 120. PTO 130 may be rotatable in clockwise and counter-clockwise directions in a 360 degree range. Linear reciprocating motion of first oscillator 110 and second oscillator 120 may cause PTO 130 to rotate at least partially through the permissible range. For example, linear motion of first oscillator 110 from a state shown in Fig. 2 A to a state shown in Fig. 2C may cause PTO 130 to rotate through a first segment in the counter-clockwise direction. The first segment may include a 90 degree segment. In some embodiments, the first segment may include a 45 degree segment. In some embodiments, the first segment may be between 30 degrees and 120 degrees.

[0045] System 100A may be configured such that PTO 130 extracts work from first oscillator 110 or second oscillator 120 as PTO 130 rotates through a segment. A segment of rotation of PTO 130 may correspond with a power stroke of first oscillator 110 or second oscillator 120. Segments may be variable. For example, first oscillator 110 may operate in a first stroke in which combustion in a combustion chamber causes expansion gases to reach high pressure, causing piston 113 and rod 111 to move so that energy can be extracted from mechanical motion of rod 111. The length of the power stroke may be from a combustion point to a point where an exhaust port is exposed. In some embodiments, there may also be a momentum stroke. The momentum stroke may include a portion of a stroke where piston 113 moves due to inertia even after combustion has concluded. Additional energy may be harvested from piston 113 as it is in the momentum stroke. The total length of the first stroke may be variable depending on, for example, fuel injection amount, air intake amount, ambient pressure, ambient temperature, ignition timing, or other engine operation conditions. Movement of rod 111 in a linear path may be transformed to rotative motion at PTO 130. PTO 130 may rotate in a segment corresponding to the length of the first stroke. Afterwards, PTO 130 may rotate in an opposite direction.

[0046] PTO 130 may be configured to selectively extract work from first oscillator 110 or second oscillator 120. PTO 130 may include a clutch. Engagement of the clutch may control whether work is extracted from rotation of PTO 130 or if PTO 130 is allowed to freewheel. PTO 130 may include a plurality of clutches. For example, a first clutch may be configured to be engaged when first oscillator 110 is in a power stroke. A second clutch may be configured to be engaged when second oscillator 120 is in a power stroke. Clutches may be disengaged when an oscillator is no longer generating power. Sensors may be provided to determine when an oscillator is in a power stroke. For example, a sensor may be configured to sense a position of piston 113 in cylinder 119. A sensor may be configured to determine a parameter of a component of an oscillator (e.g., position, speed, acceleration, etc., of piston 113 or rod 111). Similar sensors may be provided for second oscillator 120.

[0047] Fig. 2D illustrates a system 100 A’ that may be similar to system 100 A except that first oscillator 110 is configured to output a pulling force via rod 111. Second oscillator 120 may also be configured to output a pulling force via rod 121. System 100A’ may be at a position where first oscillator 110 is at a first point (e.g., a combustion point) while second oscillator 120 is at a second point (e.g., a maximum travel point). System 100A’ may include linkages 131, 132 configured to transfer power from rod 111 or rod 121 such that linkage 131 or linkage 132 is approximately parallel to rod 111 or rod 121, respectively, while a power stroke is occurring in an oscillator. The term “approximately parallel” may include or cover a situation where an axis of a component is within 5 degrees of being parallel with an axis of another component. For example, linkage 131 may be approximately parallel to rod 111 when linkage 131 is inclined +/- 5 degrees relative to rod 111. A system may be configured such that a linkage is approximately parallel to a corresponding rod during a predetermined portion of a stroke. For example, linkage 131 may be configured to be approximately parallel to rod 111 for at least 50% of a power stroke of first oscillator 110. The predetermined portion of the stroke may be from the combustion point to the beginning of an exhaust phase (e.g., a point where an exhaust port in cylinder 119 is exposed). In some embodiments, the predetermined portion of the stroke may be from the combustion point to the end of a momentum stroke portion.

[0048] In some embodiments, a linear engine system may include a combustion chamber having a first combustion side and a second combustion side. The combustion chamber may be included in an oscillator. The first combustion side may be opposite the second combustion side. The system may include a piston assembly within the combustion chamber. The piston assembly may have a first face for compressing gas on the first combustion side and a second face for compressing gas on the second combustion side. For example, the piston may include a double-sided piston, with the first face being one side of the piston and the second face being the opposite side of the piston. The piston assembly may be configured to reciprocate between the first combustion side and the second combustion side to alternatively compress gas on the first combustion side and on the second combustion side. As the piston gets closer to a first end of the combustion chamber (e.g., where the first combustion side is formed), gas in the first combustion side may be compressed and eventually may ignite. As the piston gets closer to a second end of the combustion chamber (e.g., where the second combustion side is formed), gas in the second combustion side may be compressed and eventually may ignite.

[0049] There may be provided at least one piston rod connected to the piston assembly. The at least one piston rod may include piston rod sections, e.g., with one section being on each side of a double-sided piston. In some embodiments, a piston assembly and piston rod may be formed integrally. The piston rod may extend within the combustion chamber on opposing sides of the piston assembly. The piston rod may exit the combustion chamber on the first combustion side. The piston rod may also exit the combustion chamber on the second combustion side.

[0050] There may also be provided a power take off (PTO). The PTO may be mechanically connected to the at least one piston rod. The PTO may transfer power delivered through the at least one piston rod to perform external work.

[0051] A pump may be provided that is mechanically connected to the at least one piston rod. The pump may be configured to supply gas to the combustion chamber. The pump may include an air pump, compressor, or any device with a mechanism used to move gas to be communicated to other parts of the system. The pump may move or compress gas and supply it to the combustion chamber at an elevated pressure relative to ambient pressure. The pump may be configured to act as a turbocharger.

[0052] There may also be provided at least one channel. The at least one channel may interconnect the pump and the combustion chamber to alternatively supply air to the first combustion side and the second combustion side. In some embodiments, the pump may include a compressor configured to deliver compressed gas to the first combustion side and the second combustion side.

[0053] Fig. 3A illustrates a system 100B that may be an example of oscillating system 100. System 100B may include a linear engine system. First oscillator 210 may include a linear reciprocating engine. First oscillator 210 may include a double-sided piston 213 configured to reciprocate in a linear path in a cylinder 219. Piston 213 may be attached to rod 111 that may include a first piston rod portion on a first side of piston 213 and a second piston rod portion on a second side of piston 213. Rod 111 may be an example of at least one first piston rod. A first combustion chamber 215 may be formed in an upper part of cylinder 219 of first oscillator 210. A second combustion chamber 217 may be formed in a lower part of cylinder 219 of first oscillator 210. Rod 111 may be configured to reciprocate in a linear path together with piston 213.

[0054] First oscillator 210 may be configured to generate work that is transferred to PTO 130 via rod 111. Rod 111 may include a plurality of piston rod portions. For example, at least one piston rod may include a first piston rod portion on a first side of a piston and a second piston rod portion on a second side of the piston. In some embodiments, rod 111 may be a monolithic rod. Rod 111 may be integrally formed with a first piston rod portion on a first side of piston 213 and a second piston rod portion on a second side of piston 213. A gas transmission portion 211 may be provided in the second piston rod portion. Gas transmission portion 211 may be configured to facilitate gas transmission between an interior volume of rod 111 to locations outside of rod 111. Gas transmission portion 211 may be a part of rod 111. Rod 111 may include a channel (e.g., a passageway) configured to communicate gas flow between regions on opposite sides of piston 213. For example, rod 111 may include hollow portions on either side of piston 213 and an interconnecting flow passageway through piston 213. Rod 111 may include openings configured to communicate gas flow into interior spaces of cylinder 219. Gases may be supplied to first oscillator 210 via rod 111 that may introduce gases to combustion chambers 215 and 217. For example, air may be introduced from gas transmission portion 211 and carried through rod 111 to be delivered into first combustion chamber 215 or second combustion chamber 217 via openings. The openings may be provided in rod 111 on either side of piston 213. Gas transmission portion 211 may include an open end. Air may be received through the open end of gas transmission portion 211. First oscillator 210 may include a one-way air inlet system. For example, air may be introduced from one side of first oscillator 210 to supply both combustion chambers 215, 217. A one-way valve may be provided along the path of air flow to first oscillator 210.

[0055] A system may include at least one channel that interconnects oscillators (e.g., first oscillator 210 and second oscillator 220). The at least one channel may interconnect a pump (e.g., a compressor) and a combustion chamber. The at least one channel may include a conduit connecting the oscillators. The at least one channel may be configured to alternatively deliver compressed gas to a first combustion side and a second combustion side of the combustion chamber. Gas may continuously flow through the at least one channel. A rod having openings provided therein may act as a sliding valve that may selectively provide gas to the first combustion side and the second combustion side of the combustion chamber. [0056] System 100B may include a communicator 230 that may be an example of a channel. Communicator 230 may be configured to communicate gases between first oscillator 210 and second oscillator 220. Communicator 230 may include a U-shaped tube. Communicator 230 may change a flow direction of gas output from one of first oscillator 210 and second oscillator 220 and input to the other of first oscillator 210 and second oscillator 220.

[0057] Second oscillator 220 may include a pump. The pump may be an air pump. Second oscillator 220 may include a piston 223 configured to compress gas (e.g., air) in first chamber 225 or second chamber 227. Piston 223 may be a double-sided mover. Second oscillator 220 may be powered by receiving input from PTO 130. Second oscillator 220 may receive work via rod 121. Rod 121 may transmit pushing and pulling forces to piston 223. Piston 223 may compress air in first chamber 225 or second chamber 227. Piston 223 may include valves configured to allow compressed air to be transmitted out of cylinder 229. Rod 121 may include a gas transmission portion 221 configured to transmit gases out of cylinder 229. Gas transmission portion 221 may include a hollow tube.

[0058] Piston 223 of second oscillator 220 may include one-way valves (e.g., reed valves). For example, a valve on a first side of piston 223 may be in direct communication with first chamber 225. When piston 223 moves toward the upper side of cylinder 229 (in the view of Fig. 3A), air in first chamber 225 may be compressed. Compressed air in first chamber 225 may travel through the one-way valve on the first side of piston 223 and may be communicated to communicator 230 via gas transmission portion 221. Gas may then be supplied to first oscillator 210, which may include an engine, for example by way of gas transmission portion 211. Valves may be configured to open upon reaching a predetermined pressure. For example, valves in piston 223 may be configured to open and communicate gas to communicator 230 when the gas on the other side of the valves reaches a certain pressure, and thus pressurized air may be supplied to communicator 230.

[0059] Furthermore, piston 223 may include a one-way valve on a second side of piston 223 opposite the first side. When piston 223 moves toward the bottom side of cylinder 229 (see Fig. 3B), air in second chamber 227 may be compressed. Compressed air in second chamber 227 may travel through the one-way valve on the second side of piston 223 and may be communicated to communicator 230 via gas transmission portion 221. Air may be supplied to cylinder 219 via openings in a wall of cylinder 219 (not shown).

[0060] In some embodiments, second oscillator 220 may include a linear generator, a hydraulic pump, or any actuator configured to convert input energy to energy of another form. Second oscillator 220 may be configured to receive power or generate power.

[0061] Fig. 3B illustrates system 100B at an operation position different from that of Fig. 3A. In the position shown in Fig. 3B, piston 223 of second oscillator 220 may be compressing air in second chamber 227. Compressed air enters piston 223 via a one-way valve on the second side of piston 223 and travels through gas transmission portion 221 into communicator 230. The air also travels through gas transmission portion 211 of first oscillator 210 and is delivered to second combustion chamber 217, in which a combustion phase may be ending. Air delivered to second combustion chamber 217 may help in scavenging of second combustion chamber 217 by pushing out exhaust gases and replacing exhaust gases with fresh air.

[0062] Meanwhile, on the other side of piston 213, gases may be compressed in first combustion chamber 215. Gases in first combustion chamber 215 may include air delivered previously from second oscillator 220 via communicator 230 and fuel that may have been injected when piston 213 has closed off first combustion chamber 215. A combustion chamber may be closed when openings (e.g., openings in rod 111 are no longer exposed to the interior of the combustion chamber). An air-fuel mixture in first combustion chamber 215 may be compressed and may be ready for combustion, at which point combustion may occur and first oscillator may reciprocate in a reverse direction.

[0063] First oscillator 210 may include a double-sided piston and may generate power with each movement stroke. First oscillator 210 may provide both pushing and pulling forces via rod 111. Work may be transmitted to PTO 130, and PTO 130 may transform the energy of linear reciprocating motion of rod 111 to energy of another form, such as electrical energy. For example, PTO 130 may include an alternator. The alternator may be configured to generate electrical energy as PTO 130 is rotated by linear motion input by rod 111. PTO 130 may include or be coupled to a rotor. The alternator of PTO 130 may include stator coils in which current is generated when the rotor passes therethrough. The alternator may be configured to generate electrical energy of a first polarity when PTO 130 is rotated in a first direction (e.g., clockwise). The alternator may be configured to generate electrical energy of a second polarity when PTO 130 is rotated in a second direction (e.g., counterclockwise). In some embodiments, a plurality of alternators may be provided. The alternators may be tuned to configure the system to a desired operating frequency.

[0064] An electronic control unit (ECU) may be provided that monitors and controls operations of engines. In some embodiments, an ECU may be configured to determine parameters of an engine in real time as the engine is operating, and to make determinations, such as when to inject fuel, when to trigger ignition, when to engage clutches, etc., based on determined parameters. The ECU may be connected to various sensors and actuators. In some embodiments, a dedicated computing unit may act as an ECU. In some embodiments, simple processors may be provided instead of a complex computing unit. For example, rather than an ECU calculating various parameters of a piston in an engine (e.g., position, speed, etc.), a circuit may be provided that is configured to determine either a first output or a second output. The first output may correspond to a piston being in a first half of a cylinder, and the second output may correspond to the piston being in a second half of the cylinder. A sensor may be provided, such as a Hall sensor, that is configured to output either a “1” or “0.” For example, when a component attached to the piston is overlapping with the sensor, the output may be “1.” When the component attached to the piston is not overlapping with the sensor, the output may be “0.” The circuit may be configured to determine a change between “1” and “0,” and may cause an action in response. For example, in response to determining a transition from a “0” to a “1,” it may be determined that the piston has crossed the cylinder midpoint and is now in the first half of the cylinder. It may then be determined to inject fuel into the first half of the cylinder. In response to determining a transition from a “1” to a “0,” it may be determined that the piston has crossed back over the cylinder midpoint and is now in the second half of the cylinder. It may then be determined to inject fuel into the second half of the cylinder. Ignition in the combustion chambers of the cylinder may be caused by spontaneous combustion.

[0065] Flow of gases through an oscillating system may be enhanced by using a pump coupled to a PTO to supply a combustion chamber with gases. The pump may be coupled to a moving component in the combustion chamber by way of the PTO. Inertia of all moving parts may be used to further drive the system or to generate useful work. Furthermore, use of a free piston engine may allow flexible adaptation to various operating parameters. For example, the rate of reciprocation of a piston in the engine may be matched by other aspects of the system. The PTO may be adjusted to extract power based on acceleration of the piston, which may be measured in real time. The PTO may be configured to be engaged (e.g., to apply resistive force against movement of the engine to harvest energy from the engine) as soon as it is sensed that the piston changes direction (e.g., that combustion has begun). In some embodiments, values of resistance may be adjusted based on a running state of an engine (e.g., to achieve a target rate of reciprocation at idle, such as 5-20 Hz, or to achieve an optimum power output state, such as 40 Hz). [0066] Fig. 4A illustrates a system 100C that may be a further example of oscillating system 100. System 100C may include a linear engine system. Different from the embodiment of Figs. 3A-3C, in Figs. 4A-4C, the left oscillator may include a pump and the right oscillator may include an engine. That is, first oscillator 210 may include a pump. The pump may be an air compressor. Second oscillator 220 may include a combustion chamber. Piston 213 in first oscillator 210 may be a double-sided piston or mover configured to reciprocate within cylinder 219 between a first end and a second end. Piston 213 may be configured for compressing a gas such as air. Piston 223 in second oscillator 220 may be a double-sided piston configured to reciprocate within cylinder 229 between a first combustion point and a second combustion point. Piston 223 may be configured for combustion. Both piston 213 and piston 223 may be configured to reciprocate in respective linear paths, and the linear paths may be parallel to one another. First oscillator 210 and second oscillator 220 may be coupled to one another via PTO 130.

[0067] As shown in Fig. 4A, piston 213 of first oscillator 210 may include one-way valves 214u on a first side of piston 213 (e.g., top side). One-way valves 214u may be in direct communication with first chamber 215. When piston 213 moves toward the upper side of cylinder 219 (in the view of Fig. 4A), air in first chamber 215 may be compressed. Compressed air in first chamber 215 may travel through one-way valves 214u and may be communicated to communicator 230 via gas transmission portion 211. Gas may then be supplied to second oscillator 220 by way of gas transmission portion 221. The path of intake air Ai is indicated with arrows in Fig. 4A.

[0068] Valves in piston 213 may be configured to open upon reaching a predetermined pressure. For example, one-way valves 214u may be configured to open and communicate gas to communicator 230 when the gas in first chamber 215 reaches the predetermined pressure. Pressurized air may be supplied to communicator 230 and then input to second oscillator 220. Piston 223 may be configured so that the predetermined pressure is customizable. For example, one-way valves 214u may be constructed with a certain stiffness so that they do not begin to open until the predetermined pressure is reached.

[0069] Gas may be supplied to combustion chambers of second oscillator 220 by way of openings in the at least one piston rod coupled to piston 223. For example, rod 121 may include opening 224 on a first side of piston 223 and opening 222 on a second side of piston 223. There may also be a passage through the at least one piston rod and piston 223 communicating opening 222 to opening 224. Openings 222 and 224 may be configured to be blocked (e.g., obstructed) such that gases do not escape therefrom at certain positions of the stroke of piston 223. Openings 222 and 224 may be configured to alternately supply first combustion chamber 225 and second combustion chamber 227 as piston 223 reciprocates. [0070] At the point illustrated in Fig. 4A, intake air Ai may travel from first chamber 215 in first oscillator 210, where it may be compressed by piston 213, to first combustion chamber 225 in second oscillator 220, where it may be mixed with fuel and later combusted. Intake air Ai may travel through communicator 230, through gas transmission portion 221, through piston 223, and through rod 121 and may exit by opening 224, thereby entering first combustion chamber 225.

[0071] In some embodiments, second oscillator 220 may be configured to perform scavenging for at least a portion of the stroke of piston 223. For example, as shown in Fig. 4A, intake air Ai may be supplied to first combustion chamber 225 while exhaust ports 228 are open. Prior to the point shown in Fig. 4A, combustion may have already occurred in first combustion chamber 225. Thus, introduction of intake air Ai in first chamber 225 may push out exhaust gases and replace burned combustion products with fresh air. This may help to cool cylinder 229 and remove non-combustible material (e.g., burned fuel) from first chamber 225 so that more powerful combustion may occur in the next stroke. Exhaust gases may exit cylinder 229 through exhaust ports 228.

[0072] Meanwhile, at the point shown in Fig. 4A, combustion may be ready to occur in second combustion chamber 227. Intake air may have already been supplied to second combustion chamber 227, fuel may be added, and the fuel-air mixture may have been compressed to a small volume. Ignition may occur in second combustion chamber 227, causing piston 223 to reverse direction (e.g., begin to move upwards in the view of Fig. 4A). Ignition may occur using an igniter (e.g., by actuating a spark plug), or by spontaneous combustion, for example. As the fuel-air mixture in second combustion chamber 227 is compressed, pressure and temperature rise, while volume is decreased. As long as gases are contained in second combustion chamber 227, piston 223 is prevented from contacting the bottom of cylinder 229. Eventually, a spontaneous combustion point may be reached. Additional materials may also be present in combustion chamber 227, such as water, which may be a product of previous combustion. Regardless of the composition of the fuel-air mixture in second combustion chamber 227, because no external spark may be needed for ignition, combustion may still occur in combustion chamber 227 by self-ignition even in the presence of some water. As piston 223 continues to move through its stroke, it will eventually be stopped by self-ignition, reaching a combustion point, and will begin to move in the opposite direction.

[0073] As shown in Fig. 4B, piston 223 may be moving upwards as combustion proceeds in second combustion chamber 227. The pressure of expanding gases in second combustion chamber 227 may force piston 223 toward the other end of cylinder 229. At the point shown in Fig. 4B, openings 222 and 224 in the at least one piston rod may be obstructed. Also, exhaust ports 228 may be blocked by piston 223. Thus, there is no gas communication into or out of first combustion chamber 225 or second combustion chamber 227. Meanwhile, as piston 223 moves by the power of combustion, PTO 130 is rotated by rod 121 and power may be extracted.

[0074] At the point shown in Fig. 4C, opening 222 in rod 211 may be exposed to the interior of second combustion chamber 227, and intake air Ai may be supplied thereto. A scavenging phase may begin in second combustion chamber 227 when opening 222 begins to be uncovered. Meanwhile, opening 224 may be blocked (e.g., by virtue of no longer being exposed to the interior of first combustion chamber 225) and no air escapes from opening 224. Also, compression of gases in first oscillator 215 may be occurring on an opposite side of piston 223.

[0075] Piston 223 may include one-way valves 214d on a second side of piston 223 (e.g., bottom side) opposite the first side. When piston 223 moves toward the bottom side of cylinder 219 (see Fig. 4C), air in second chamber 217 may be compressed. Compressed air in second chamber 217 may travel through one-way valves 214d and may be communicated to communicator 230 via gas transmission portion 211. Air may be supplied to cylinder 229 via rod 121. As opening 224 may be blocked, and only opening 222 is exposed to the interior of second combustion chamber 227, intake air Ai may be supplied to second combustion chamber 227.

[0076] Reference is now made to Figs. 5A-5C, which illustrate overall views of a system that may be useful for power generation, consistent with embodiments of the disclosure. Fig. 5A is a front view of a system 500. System 500 includes first oscillator 510, second oscillator 520, and PTO 530. Fig. 5A shows components of system 500 supported by frame 550. There is also provided a battery unit 560, exhaust unit 540, exhaust tubing 542, and communicator 533. Sensor 534 is provided on communicator 533. System 500 may include a linear engine system. Sensor 534 may include an air flow sensor, such as a mass air flow (MAF) sensor or manifold absolute pressure (MAP) sensor. Exhaust unit 540 may include a muffler.

[0077] Fig. 5B is a rear view of system 500. Fig. 5B shows fuel injector 561 provided on second oscillator 520. Fig. 5B also shows first sensor 536 and second sensor 537 provided on communicator 533. First sensor 536 may be configured to detect a component of first oscillator 510. Second sensor 537 may be configured to detect a component of second oscillator 520. First and second sensor 536, 537 may include Hall sensors. First and second sensors 536, 537 may be configured to determine whether or not a component of an oscillator, such as a piston rod, is overlapping with the respective sensor. For example, first sensor 536 may be configured to determine whether a rod that moves together with a piston overlaps with first sensor 536. First sensor 536 may be configured to have binary output (e.g., output “1” if the rod is detected in proximity or output “0” if nothing is detected). First and second sensors 536, 537 may include sensors such as those discussed in U.S. Patent No. 11,008,959, which is hereby incorporated by reference in its entirety. First sensor 536 may detect rod 511 when it is in a lower position (see Fig. 6A) and second sensor 537 may detect rod 521 when it is in a lower position (see Fig. 6C).

[0078] Fig. 5C is a side view of system 500. Fig. 5C shows an ECU 570 mounted on frame 550. ECU 570 may be configured to control operations of system 500. Various electronics may be provided, such as a charge controller, battery regulator, any computer configured to be electronically coupled to sensors of system 500, or any computer configured to issue a control signal to a component of system 500. ECU 570 and other electronic devices, such as sensors and actuators, may be connected to one another. Such connections may be wired or wireless.

[0079] Reference is now made to Figs. 6A-6E, which are diagrammatic representations of a linear engine system, consistent with embodiments of the disclosure. The views of Figs. 6A-6E may correspond to cross section A-A shown in Fig. 5C. Figs. 6A-6E may represent internal components of system 500. As shown in Figs. 6A-6E, components may be movable between various positions.

[0080] A power take off (PTO) may include a body configured to receive mechanical input and to output another form of energy. A PTO may be moved by mechanical motion of an input member and may output energy to be used for work. For example, the PTO may receive mechanical back-and-forth reciprocating motion from an engine (that converts chemical energy into mechanical motion), and the PTO may power a generator to output electrical power. The PTO may be moved by input motion in a linear manner, rotative manner, or any other kinematic manner. The PTO may be moved in a various directions based on the manner of input. The PTO may be moved in a first direction when combustion occurs in a first combustion chamber of an engine that is connected to the PTO. The PTO may be moved in a second direction when combustion occurs in a second combustion chamber of an engine that is connected to the PTO. The first and second directions may be different from one another, and may be opposite.

[0081] As shown in Fig. 6A, 530 may include a rotative body, such as a disc. PTO 530 is mechanically coupled to first oscillator 510 and to second oscillator 520. PTO 530 is connected to rod 511 of first oscillator 510 via first linkage 531, and PTO 530 is connected to rod 521 of second oscillator 520 via second linkage 532. Linkages 531 and 532 each include two pivot points. First oscillator 510 is a pump, and second oscillator 520 is a linear reciprocating engine. First oscillator 510 includes piston 513 configured to move between a first end of a first cylinder 519 and a second end of first cylinder 519. Piston 513 is connected to rod 511. Second oscillator 520 includes piston 523 configured to move between a first combustion point at a first end of second cylinder 529 and a second combustion point at a second end of second cylinder 529. [0082] At the point shown in Fig. 6A, air may be pumped from a second chamber 517 of first oscillator 510 to a second combustion chamber 527 of second oscillator 520.

Combustion may be about to occur in a first combustion chamber 525 of second oscillator

520. The location of piston 523 shown in Fig. 6A may correspond to a first combustion point. Exhaust ports 528 may be exposed, and a scavenging phase may be occurring in second combustion chamber 527 while exhaust gases from a previous combustion phase in second combustion chamber 527 exit through exhaust ports 528. Intake air may be supplied to second combustion chamber 527 of second oscillator 520 via openings 522 in piston rod

521. Openings 522 include angled openings so as to impart a swirl effect on air entering second combustion chamber 527. Air is pumped from first oscillator 510 as piston 513 compresses air in second chamber 517, increasing its pressure so as to open one-way valves 514d on a lower side of piston 513. Air travels from one-way valves 514d through opening 514 into communicator 533. Sensor 534 measures flow characteristics of the gas passing through communicator 533. Air may be drawn from inlet 580d, which is part of inlet unit 580 (see Fig. 7A) together with inlet 580u.

[0083] As shown in Fig. 6B, combustion in first combustion chamber 525 of second oscillator 520 may cause piston 523 to move away from the first combustion point and towards a second combustion point. This motion causes PTO 530 to rotate as a pulling force is transferred through linkage 532. Linkage 531, also coupled to PTO 530, in turn transfers a pulling force to rod 511, causing piston 513 to move in a direction opposite that of piston 523. As piston 523 moves in a first direction (e.g., down in Fig. 6B), piston 513 moves in a second direction (e.g., up in Fig. 6B). Air, having been drawn into first chamber 515 of first oscillator 510 from inlet 580u as the volume of first chamber 515 was increasing, may now begin to be compressed as piston 513 moves toward first chamber 515 and decreases the volume of first chamber 515. Inlet 580u and inlet 580d include one-way valves so that air can be drawn into first oscillator 510 but is not pushed back out through inlet unit 580.

[0084] PTO 530 moves in a first direction (e.g., clockwise) when combustion is occurring in first combustion chamber 525, and moves in a second direction (e.g., counterclockwise) when combustion is occurring in second combustion chamber 527. [0085] In some embodiments, instead of a disc, for example, PTO 530 may include a linear member. The linear member of PTO 530 may be configured to move in a first direction (e.g., down in Fig. 6B) when combustion is occurring in first combustion chamber 525, and the linear member may be configured to move in a second direction (e.g., up) when combustion is occurring in second combustion chamber 527. Furthermore, first and second linkages 531, 532 may be connected directly to one another. For example, first oscillator 510 and second oscillator 520 may be aligned in a linear direction (e.g., the same linear direction that piston 523 is configured to reciprocate along). Various configurations and form factors are possible. For example, when first oscillator 510 and second oscillator 520 are aligned, a long and thin system may be implemented. Particular applications may call for particular form factors.

[0086] Compression may occur simultaneously in first oscillator 510 and second oscillator 520. For example, gases may be compressed in first chamber 515 of first oscillator 510 as gases are compressed in second combustion chamber 527 of second oscillator 520. Likewise, gases may be compressed in second chamber 517 of first oscillator 510 as gases are compressed in first combustion chamber 525 of second oscillator 520. The gases compressed in first oscillator 510 may include fresh air, and the gases compressed in second oscillator 520 may include ignition gases (e.g., a fuel-air mixture).

[0087] Oscillators may be configured to perform complementary actions. First oscillator 510 may supply air to a combustion chamber of second oscillator 520 while gases are compressed in a different combustion chamber of the second oscillator. For example, as piston 523 moves toward the first combustion point (e.g., the upper end of cylinder 529), gases may be compressed in first combustion chamber 525 while compressed gases are supplied to second combustion chamber 527 by first oscillator 510. The act of compressing gases in first combustion chamber 525 may require energy (that may usually be supplied by combustion in second combustion chamber 527), however the further introduction of compressed gases into second combustion chamber 527 may help to further work to move piston 523 toward the first combustion point and compress the fuel-air mixture in first combustion chamber 525. [0088] Continuing in the sequence of Figs. 6A-6E, at the point shown in Fig. 6C, piston 523 may continue to move toward the second combustion point. Gases in second combustion chamber 527 may be compressed until the second combustion point is reached. Meanwhile, air may be pumped from first chamber 515 of first oscillator 510 to first combustion chamber 525 of second oscillator 520. Combustion may be about to occur in second combustion chamber 527 of second oscillator 520. The location of piston 523 shown in Fig. 6C may correspond to the second combustion point. Exhaust ports 528 may be exposed, and a scavenging phase may also be occurring in first combustion chamber 525 while exhaust gases from the prior combustion phase in first combustion chamber 525 exit through exhaust ports 528. Intake air may be supplied to first combustion chamber 525 of second oscillator 520 via openings 524 in piston rod 521. Openings 524 include angled openings so as to impart a swirl effect on air entering first combustion chamber 525. Air is pumped from first oscillator 510 as piston 513 compresses air in first chamber 515, increasing its pressure so as to open one-way valves 514u on an upper side of piston 513. Air travels from one-way valves 514u through opening 514 into communicator 533. Sensor 534 measures flow characteristics of the gas passing through communicator 533. Air may be drawn from inlet 580u.

[0089] Next, at the point shown in Fig. 6D, a power stroke may be occurring as piston 523 moves from the second combustion point toward the first combustion point. A pushing force may be transferred to PTO 530 via linkage 532. Following a combustion phase in second combustion chamber 527, piston 523 may still have momentum and may continue moving toward the first combustion point in a momentum phase, even as combustion gases have ceased expanding and begin to exit through exhaust ports 528. This momentum phase may be assisted as air is pumped into second combustion chamber 527 from first chamber 515 of first oscillator 510. Thus, a higher compression ratio in first combustion chamber 525 may be attained. Furthermore, the increased supply pressure of air input into the combustion chamber next undergoing combustion (in this case, second combustion chamber 527 in the state shown in Fig. 6D) may allow second oscillator 520 to perform more powerful combustion and achieve greater compression effects in the opposing combustion chamber in the next cycle. [0090] Fig. 6E shows the completion of the power stroke of piston 523 moving from the second combustion point to the first combustion point (e.g., upwards in the view of Fig. 6E). This power stroke may correspond to pushing forces transmitted to PTO 530 via linkage 532. Thereafter, the next power stroke may begin in which pulling forces are transmitted to PTO 530 via linkage 532 as piston 523 moves from the first combustion point to the second combustion point (e.g., downwards in the view of Fig. 6E). As PTO 530 is caused to move by motion of second oscillator 520, power may be harvested. Cycles may repeat and power may continue to be harvested (e.g., by generating electric power).

[0091] Figs. 7A-7E illustrate a first oscillator and an inlet unit, consistent with embodiments of the disclosure. As shown in Fig. 7A, there may be provided inlet unit 580 that is connected to first oscillator 510. Inlet unit 580 may include air filter 589. There may also be provided a throttle configured to control an amount of air that flows into inlet unit 580. Inlet unit 580 may supply both first chamber 515 and second chamber 517 of first oscillator 510. Inlet unit 580 may include inlet 580u and inlet 580d. Air entering from inlet 580u may pass through a one-way valve and may pass through opening 581 to enter first chamber 515. Air entering from inlet 580d may pass through a one-way valve and may pass through opening 582 to enter second chamber 517.

[0092] As shown in Fig. 7B, piston 513 includes one-way valves 514d on a lower side of piston 513. One-way valves 514d may be configured to allow gas to pass therethrough only when pressure in second chamber 517 reaches a predetermined pressure.

[0093] As shown in Fig. 7C, piston 513 also includes one-way valves 514u on an upper side of piston 513. One-way valves 514u may be configured to allow gas to pass therethrough only when pressure in first chamber 515 reaches a predetermined pressure that may be the same or different from that with respect to one-way valves 514d. One-way valves 514u may include a resilient member, such as a flap. The resilient member may begin to flex when the predetermined pressure is reached, opening a gas communication path. One-way valves 514d may be similarly configured. There may also be provided backer plates that support the flaps to prevent the flaps from flexing excessively. The backer plates may be configured to allow the flaps to open a predetermined amount (e.g., to open no more than 45 degrees). [0094] Air or other gas introduced into first oscillator 510 may be compressed as piston

513 reciprocates back-and-forth between a first end of cylinder 519 and a second end of cylinder 519. Air may be pushed through one-way valves 514u or 514d and through opening

514 to reach communicator 533. Then, air may be supplied into second oscillator 520.

[0095] Although the above embodiment uses compressed air to supply second oscillator 520, in some embodiments of the disclosure, air may be allowed to flow into a combustion chamber using vacuum or suction.

[0096] Energy extraction from PTO 530 may be performed in various ways as PTO 530 is caused to move. In some embodiments, an alternator may apply a resistive force to PTO 530 as it is urged to rotate by motion of second oscillator 520. A higher resistance may correspond to greater generation of electric energy. PTO 530 may be configured to extract more energy the fast that components of second oscillator 520 are moving. Positions of components may be monitored by sensors, such as first sensor 536 and second sensor 537 (see Fig. 5B). Sensors may be configured to detect components of first oscillator 510 or second oscillator 520, respectively. For example, first sensor 536 may be configured to detect an edge of rod 511, and second sensor 537 may be configured to detect an edge of piston rod 521. Sensors may be used to measure the acceleration of components, such as rod 511 or piston rod 521. The determined acceleration may be used to determine resistance to be applied to PTO 530.

[0097] A method of operating a system according to embodiments of the disclosure may include adjusting an amount of power to take off from a power take off (PTO) of a linear engine system. Adjusting the amount of power to take off may include adjusting an amount of resistant applied to the PTO. The adjustment of the amount of power to take off may be based on a determined parameter of the linear engine system. For example, a parameter of a piston rod connected to a piston configured to reciprocate in a combustion chamber may be determined. The parameter may include position, speed, acceleration, or any other detectable physical parameters of the system. The parameter may be of the piston rod or any moving component of the linear engine system, such as the piston, linkage, or of the PTO itself. In some embodiments, the PTO may be coupled to other components, such as a pump, and thus a parameter of the other components (e.g., a rod of the pump) may be determined that are indicative of other aspects of the system. For example, a relationship may be found relating a speed of rod 511 of first oscillator 510 to piston rod 521 of second oscillator 520. In some embodiments, a speed of rod 511 of first oscillator 510 may be directly proportional to a speed of piston rod 521 of second oscillator 520. Acceleration of either component may be used to determine operational parameters of the linear engine system, such as a resistance to be applied to the PTO. The PTO may be configured to offer a variable resistance. The variable resistance may be applied via one or more clutches or by application of a voltage to an electrical apparatus of the PTO.

[0098] In some embodiments, a method of controlling a linear engine system may be provided. The method may include determining a parameter of the linear engine system. Determining the parameter may be performed using a first sensor or a second sensor. The first sensor may be configured to determine a parameter of a first oscillator. The second sensor may be configured to determine a parameter of a second oscillator. An example of the first sensor may include first sensor 536 and second sensor 537 discussed above with respect to Fig. 5B Each of the first and second sensors may themselves include one or more sensors (e.g., a position sensor and a speed sensor). The parameter may include a position, speed, acceleration, movement direction, or any other detectable physical parameter of the system. In some embodiments, one or both of the first and second sensors may be used to determine the parameter of the first oscillator, or the parameter of the second oscillator.

[0099] The parameter of the linear engine system may be a parameter of an oscillating mass of the first oscillator or the second oscillator. The oscillating mass may include any moving components of the first oscillator or of the second oscillator. For example, the oscillating mass may include a piston assembly. The oscillating mass may include at least one piston rod connected to the piston assembly. The oscillating mass may include linkages connected to the at least one piston rod. The oscillating mass may include a rotative body of a power take off that is mechanically coupled to the at least one piston rod. The oscillating mass may include other components that may form part of the momentum of the piston assembly or its connected components. The parameter of the oscillating mass may include piston speed. The parameter of the oscillating mass may include piston acceleration. The parameter may be indicative of the energy of the oscillating mass. For example, the parameter may indicate the amount of kinetic energy of the oscillating mass that may be imparted to it by combustion.

[00100] Various types of sensors may be used to determine parameters that may be indicative of operation states of a linear engine system. Further, more than one sensor may be provided to monitor parameters of a single oscillator. Sensors may be provided on either or both of the first and second oscillators. A sensor may be provided that is configured to determine whether a piston is in a first region of a cylinder or a second region of the cylinder. The first region may be a first half of the cylinder and the second region may be a second half of the cylinder. The sensor may also determine whether the piston is at the midpoint of the cylinder. The sensor may also detect transitions of the piston from being in the first region or the second region. For example, a first sensor of a first oscillator may be configured to determine a first output or a second output, the first output corresponding to the piston being in the first region of a cylinder, and the second output corresponding to the piston being in the second region of the cylinder. The first sensor may output “1” if a component connected to the piston is adjacent the first sensor of the first oscillator, and may output “0” if no component is adjacent the first sensor of the first oscillator. The first sensor of the first oscillator may include a Hall sensor. The first sensor of the first oscillator may include any electromagnetic sensor configured to detect a change using electromagnetism.

[00101] A second sensor of the first oscillator may also be provided. The second sensor of the first oscillator may be configured to detect an increment in response to a component of the first oscillator passing a region of the second sensor of the first oscillator. The second sensor of the first oscillator may determine increments of movement of the piston of the first oscillator in the cylinder. For example, the second sensor of the first oscillator may determine that the piston has moved a predetermined distance (e.g., one increment) in a certain period (e.g., in one or more clock cycles of the second sensor). The second sensor may include a piston speed sensor. The second sensor may be configured to correlate a parameter of an oscillating mass of the first oscillator to an energy of the oscillating mass. In some embodiments, the second sensor may include a trigger disk configured to detect a number of teeth that are moved due to movement of the piston. [00102] In some embodiments, only one sensor may be provided. The only one sensor may be the first sensor or the second sensor. For example, in some embodiments, only a binary output sensor may be provided on one oscillator. In some embodiments, only a speed sensor may be provided on one oscillator.

[00103] Further, the first sensor or second sensor may be configured to determine parameters upon pistons or other components reaching a reference point. For example, the first sensor may determine the parameter upon the piston in the first oscillator reaching the midpoint of the cylinder. In some embodiments, the reference point may be set to a location at or just after a combustion point. Setting a reference point close to the combustion point may help to accurately identify the energy of the oscillating mass imparted by combustion. In some embodiments, a controller may be configured to adjust the reference point. Adjustments of the reference point may be based on a prior operation of oscillators.

[00104] A controller, such as an ECU, may determine a reciprocation rate of a piston of an oscillator based on sensor output. For example, a reciprocation rate of a first oscillator may be based on the number of times the output of the first sensor changes. This may correspond to the number of times the piston changes direction in the cylinder. Based on the frequency of the reciprocation of the piston, operation parameters of the linear engine system may be adjusted.

[00105] Operation parameters of the linear engine system may include an amount of a variable resistance of a PTO, application of the variable resistance (e.g., via engagement of clutches), throttle opening amount, fuel injection amount, fuel injection timing, timing of application of the variable resistance, and other parameters that may affect the operation of the linear engine system.

[00106] An ECU may determine parameters of a linear engine system (e.g., piston speed), and a variable resistance of a PTO of the linear engine system may be adjusted. For example, the faster the piston reciprocates (e.g., the greater Hz of the engine), the heavier the variable resistance may be, so as to extract more power from a power-producing engine of the linear engine system. The variable resistance may also be adjusted in accordance with a demand (e.g., an external load). The demand may correspond to an electrical load needed to charge a battery. The variable resistance may be adjusted based on various criteria. The variable resistance may be adjusted to achieve a target operation state of the engine. For example, the variable resistance may be adjusted to maintain a target reciprocation rate (Hz) of the engine. The variable resistance may be incremented or decremented according to the criteria (e.g., external demand) or determined parameters (e.g., sensor output).

[00107] Other methods consistent with embodiments of the disclosure may include determining an amount of fuel to inject, determining operating parameters of a generator, identifying positions of components in a linear engine system (e.g., positions of pistons within cylinders), and other functions related to operation of engines. In some embodiments, a generator may harvest power from an engine. Also, the generator may provide power (e.g., instead of providing a resistance to motion generated by the engine, the generator may use electrical energy to move the engine). The generator may be useful in starting the linear engine system.

[00108] In some embodiments, an ECU may perform methods discussed herein. The ECU may receive information from sensors and may output control signals to components of a linear engine system. The ECU may perform calculations. For example, a determined parameter may include piston speed. The ECU may determine piston acceleration by determining the first derivative of piston speed with respect to time. The ECU may perform calculations at the reference point.

[00109] To expedite the foregoing portion of the disclosure, various combinations of elements are described together. It is to be understood that aspects of the disclosure in their broadest sense are not limited to the particular combinations previously described. Rather, embodiments of the invention, consistent with this disclosure, and as illustrated by way of example in the figures, may include one or more of the following listed features, either alone or in combination with any one or more of the following other listed features, or in combination with the previously described features.

[00110] For example, there may be provided a power generation system including an engine. The engine may include a cylinder having a combustion chamber included therein; a piston slidably mounted within the cylinder, and a piston rod extending beyond the cylinder. There may also be provided the following elements: • a PTO configured to transform linear reciprocating motion of the engine to energy of another form;

• wherein the system is balanced about a vertical axis;

• wherein the vertical axis divides the system into a left half and a right half, the engine provided in one of the left half and the right half;

• wherein the engine includes a plurality of engines;

• wherein a first engine is provided in the left half, and a second engine is provided in the right half;

• further comprising an air pump that includes a mover, wherein the air pump is configured to supply air to the engine as the mover reciprocates together with the piston;

• wherein the piston includes a double-sided piston;

• wherein the mover includes a double-sided mover;

• wherein the engine is provided in one of the left half and the right half of the system, and the air pump is provided in the other of the left half and the right half;

• further comprising a passage from the air pump to the engine;

• wherein the passage is arranged at a bottom side of the system;

• wherein the PTO is arranged at a top side of the system;

• wherein the passage is included in a U-shaped tube that is symmetrical about the vertical axis;

• wherein the engine includes an atrium at one side, the passage communicating with the atrium;

• wherein the engine is configured to supply diesel fuel to the cylinder;

• wherein the engine is configured to supply hydrogen fuel to the cylinder;

• wherein the engine is configured to supply gasoline to the cylinder;

• wherein the piston rod includes a recess configured to supply air from the atrium into a combustion chamber of the engine;

• wherein the air pump is configured to pressurize air supplied to the engine; • wherein the piston rod is attached at one end to the PTO, and the air pump is attached at one end to the PTO;

• wherein the PTO is configured such that when the engine is at a first combustion point, a connecting member between the piston rod and the PTO is parallel to the piston rod; and

• wherein the PTO is configured such that when the engine is at a second combustion point at an opposite end of the cylinder, the connecting member between the piston rod and the PTO is parallel to the piston rod.

[00111] Furthermore, for example, there may be provided a method of securing an oscillating system. The oscillating system may include a first oscillator with a first oscillating mass and a second oscillator with a second oscillating mass. There may also be provided the following elements:

• securing the system at a first pivot point, the first pivot point aligned with an axis about which a PTO configured to transfer linear motion of the first oscillating mass to rotative motion rotates;

• securing the system at a second pivot point, the second pivot point aligned with a direction in which an engine including the first oscillating mass and an air pump including the second oscillating mass are arranged;

• securing the system to a support frame;

• counterbalancing the first oscillating mass with the second oscillating mass;

• wherein the first pivot point is supported by a first cushioning member and a second cushioning member;

• wherein the system is attached at the second pivot point by a bushing; and

• wherein the second pivot point is configured to allow the system to rotate about a direction parallel to a direction of reciprocation of the first oscillating mass or the second oscillating mass.

[00112] Furthermore, for example, there may be provided an energy transfer apparatus having elements including:

• a rotative member configured to rotate about a first axis;

• an engine configured to input work to the rotative member; • wherein the rotative member is configured to transform linear reciprocating motion from the engine to energy of another form;

• wherein the energy of another form includes rotative motion;

• wherein the energy of another form includes electrical energy;

• wherein the energy of another form includes hydraulic energy;

• wherein the rotative member includes an alternator;

• wherein the alternator includes a plurality of alternators;

• wherein the alternator includes a rotor and a stator;

• a first linkage including a first connecting member configured to connect a linear reciprocating engine to the rotative member such that when the linear reciprocating engine is at a first combustion point, the first connecting member is parallel to a direction of reciprocation of the linear reciprocating engine;

• a second linkage including a second connecting member configured to connect an air pump to the rotative member such that when the air pump is at a position of maximum travel, the second connecting member is parallel to a direction of reciprocation of the air pump;

• wherein the rotative member is configured such that when the engine is at a second combustion point at an opposite end of the cylinder, the connecting member between the piston rod and the PTO is parallel to the piston rod;

• wherein the rotative member is configured to reverse direction with every stroke of the engine; and

• wherein the rotative member is configured such that the first connecting member is parallel to the second connecting member when the air pump is at the position of maximum travel.