Free piston power generation device

Abstract

The invention provides a free piston power generation device, which comprises a generator, an engine and a magnetic crankshaft module, and is characterized in that the magnetic crankshaft module is internally provided with a crankshaft rotor which is connected with a motor rotor and synchronously rotates along with the motor rotor, and the surface of the crankshaft rotor is provided with a spiral magnetic array; the crankshaft rotor is connected with the piston and synchronously moves along with the piston, and a rotor magnetic array is arranged on the crankshaft rotor; and the spiral magnetic array and the rotor magnetic array are magnetically matched, so that the unidirectional rotation of the crankshaft rotor is linked with the reciprocating translation of the crankshaft rotor. According to the free piston power generation device, the magnetic crankshaft module is additionally arranged, the defect that a rotor of a traditional free piston engine cannot store energy is overcome, and the power generation power and efficiency are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of free piston generators, and in particular relates to a free piston generator. Background Art

[0002] The free piston generator originated in the United States in 1940. In the past two decades, due to the development of rare earth permanent magnets and power electronics technology, many research teams have been committed to researching lighter and more efficient prototypes in this field. At present, most of the research in this field is based on free piston generators with linear motors. The advantages of this type of device are its relatively simple structure, fewer moving parts and relatively variable compression ratio, so the structure can be designed to be more compact and can adapt to different types of fuels. However, the disadvantage is that it does not have a rotating structure that can store energy, so an additional linear reset system is required, or a double-opposing structure is used, which requires a complex linear load control system.

[0003] Therefore, the current main research challenge of free piston generators is how to solve the energy storage problem and avoid complex linear load control while ensuring the compactness of the free piston generator. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a free piston generator to solve the energy storage problem of the free piston generator.

[0005] The present invention achieves the above technical objectives through the following technical means.

[0006] A free piston power generation device, comprising:

[0007] A generator, in which a motor rotor is arranged;

[0008] The engine is a free piston engine having a piston therein;

[0009] The magnetic crankshaft module includes:

[0010] A crankshaft rotor is connected to the motor rotor, rotates synchronously with the motor rotor, and has a spiral magnetic array on its surface;

[0011] A crankshaft mover is connected to the piston and moves synchronously with the piston, and a mover magnetic array is provided on the crankshaft mover;

[0012] The magnetic force between the spiral magnetic array and the mover magnetic array cooperates to link the unidirectional rotation of the crankshaft rotor with the reciprocating translation of the crankshaft mover.

[0013] Further:

[0014] The spiral magnetic array is formed by axially arranging multi-pole magnetic poles in a manner that the N poles and the S poles are adjacent to each other, and each pole magnet is composed of four single magnets of the same polarity connected end to end in the circumferential direction, each single magnet is a spiral structure, and the spiral directions of two adjacent single magnets are opposite;

[0015] The mover magnetic array is a long strip structure, which is composed of multi-pole magnetic poles arranged axially in a manner that the N poles and the S poles are adjacent to each other. There are two mover magnetic arrays, which are symmetrically distributed on both sides of the spiral magnetic array.

[0016] Furthermore, the spiral magnetic array and the mover magnetic array are 6-pole.

[0017] Furthermore, an iron core is provided inside the spiral magnetic array and inside the mover magnetic array respectively. The iron core is made of HM-S4 soft magnetic composite material, and the spiral magnetic array and the mover magnetic array are made of N40SH neodymium iron boron permanent magnets.

[0018] Furthermore, the crankshaft mover includes a mover bracket, which is an annular structure and surrounds the outer side of the crankshaft rotor;

[0019] Both sides of the mover bracket are connected to the housing of the magnetic crankshaft module through linear guide shafts, and the linear guide shafts are parallel to the crankshaft rotor axis;

[0020] The mover magnetic array is arranged on the inner side of the mover bracket, and the mover magnetic array is opposite to the spiral magnetic array.

[0021] Furthermore, the crankshaft rotor is coaxial with the motor rotor.

[0022] Furthermore, the engine cylinder is connected to the housing of the magnetic crankshaft module, one side of the piston in the cylinder is a combustion chamber, and the other side is an oil and gas storage chamber; on one side of the oil and gas storage chamber, the piston is connected to the crankshaft mover through a number of connecting rods; a spark plug is provided on one side of the combustion chamber;

[0023] The side wall of the cylinder body is provided with an air inlet hole and an air exhaust hole, which are symmetrically distributed on both sides of the cylinder body, and both are provided with a one-way valve; a ventilation groove is opened at the inner end of the cylinder on one side of the oil and gas storage chamber, and an air duct is provided to connect the air inlet hole and the ventilation groove.

[0024] Furthermore, the inner cavity of the magnetic crankshaft module housing is communicated with the oil and gas storage chamber of the engine cylinder block, and the magnetic crankshaft module housing is airtight relative to the outside.

[0025] Furthermore, the crankshaft mover stroke is equal to the piston stroke.

[0026] Furthermore, the crankshaft rotor is used to store kinetic energy to push the piston back to the top dead center and maintain the motor rotor in operation during this period.

[0027] The beneficial effects of the present invention are:

[0028] (1) The present invention provides a free piston power generation device, which overcomes the disadvantage of the traditional free piston engine mover that cannot store energy by adding a magnetic crankshaft module, thereby improving the power generation power and efficiency.

[0029] (2) The present invention reduces friction loss and the risk of overload of the power generation device by utilizing the magnetic coupling contact characteristics of the magnetic crankshaft, thereby enhancing the safety of the power generation device.

[0030] (3) Compared with the traditional mechanical crankshaft mechanism, the present invention realizes the coaxial distribution of rotational motion and reciprocating motion by combining the topological characteristics of the magnetic crankshaft and the free piston, thereby reducing the complexity of the structure, reducing the number of components, and increasing the space utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is an external structural diagram of a power generation device according to an embodiment of the present application;

[0032] Figure 2 This is a cross-sectional view of a power generation device according to an embodiment of the present application;

[0033] Figure 3 This is a side oblique stereoscopic view of a generator in a half-section state of a power generation device according to an embodiment of the present application;

[0034] Figure 4 This is a side oblique perspective view of the engine of the power generation device in a half-section state according to an embodiment of the present application;

[0035] Figure 5 This is a structural diagram of the moving parts in the embodiment of the present application;

[0036] Figure 6 This is a multi-view projection diagram of the spiral magnetic array in the embodiment of the present application;

[0037] Figure 7 This is a diagram with key dimensions of the spiral magnetic array in the embodiment of the present application;

[0038] Figure 8 This is a schematic diagram of the working process of the power generation device according to an embodiment of the present application.

[0039] Reference numerals:

[0040] 1- generator; 11- motor stator; 12- stator winding; 13- motor rotor;

[0041] 14-rotary encoder; 2-magnetic crankshaft module; 21-crankshaft rotor; 22-spiral magnetic array;

[0042] 23-crankshaft mover; 24-linear guide shaft; 25-linear bearing; 26-motor core;

[0043] 27-motor magnetic array; 3-engine; 31-piston; 32-fire piston;

[0044] 33-air inlet; 34-airway; 35-ventilation slot; 36-exhaust hole;

[0045] 4-spindle; 41-bearing; 5-connecting rod. DETAILED DESCRIPTION

[0046] Embodiments of the present invention are described in detail below, examples of the illustrated embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0047] 1. Structure Description

[0048] like Figure 1 The power generation device shown includes three parts: a generator 1, a magnetic crankshaft module 2, and an engine 3, wherein the magnetic crankshaft module 2 is located between the generator 1 and the engine 3, and the engine 3 drives the generator 1 to operate and generate electricity via the magnetic crankshaft module 2.

[0049] Reference Figures 2 to 5 As shown:

[0050] 1. Generator

[0051] It includes a motor stator 11 and a motor rotor 13. The motor stator 11 is fixedly connected to the housing of the generator 1. The motor stator 11 includes a stator bracket of an annular structure, a stator core is arranged inside the stator bracket, and a centralized stator winding 12 is arranged in the stator core slot. In this embodiment, the stator bracket is made of 304 stainless steel and is fixed to the housing of the generator 1 by bolts; the stator core is made of 35A250 silicon steel sheet and is fixed to the annular bracket by pins; the stator winding 12 is made of 92% IACS1mm wire diameter enameled wire and is fixed to the stator core by slot wedges and epoxy resin.

[0052] The motor rotor 13 is located inside the motor stator 11 and can rotate relative to the motor stator 11. The motor rotor 13 is arranged on the motor shaft (main shaft 4), and both ends of the motor shaft are connected to the housing of the generator 1 through bearings 41. The motor rotor 13 includes a rotor core and a rotor magnetic array; wherein the rotor core adopts 35A250 hollow silicon steel sheet; the rotor magnetic array has 10 poles and adopts N40SH neodymium iron boron permanent magnets. One end of the motor shaft extends out of the housing of the generator 1, and a rotary encoder 14 is arranged thereon for monitoring the angular position of the motor rotor 13.

[0053] 2. Magnetic crankshaft module

[0054] It includes a crankshaft rotor 21 and a crankshaft mover 23. The crankshaft rotor 21 is rotatably connected to the housing of the magnetic crankshaft module 2 through a rotating shaft (spindle 4); in this embodiment, the rotating shaft and the motor shaft are coaxially designed, and a part of the spindle 4 penetrates into the generator 1 as the motor shaft, and a part of the spindle 4 penetrates into the magnetic crankshaft module 2 as the rotating shaft of the crankshaft rotor 21; in addition to the above-mentioned coaxial design, other methods can also be used to connect the two shafts according to actual conditions such as layout requirements. A cylindrical iron core is provided on the surface of the crankshaft rotor 21, and the cylindrical iron core is a HM-S4 soft magnetic composite material; a spiral magnetic array 22 is provided on the surface of the cylindrical iron core, and the spiral magnetic array 22 uses N40SH neodymium iron boron permanent magnets.

[0055] The crankshaft rotor 21 is required to have a sufficiently large mass to store kinetic energy and ensure that the motor rotor 13 can run smoothly without external force.

[0056] The crankshaft mover 23 is movably connected to the housing of the magnetic crankshaft module 2 through a linear guide shaft 24. There are two linear guide shafts 24, which are parallel to the main shaft 4 and symmetrically arranged on both sides of the main shaft 4, and each is fixedly connected to the housing of the magnetic crankshaft module 2 by bolts. The crankshaft mover 23 includes a mover bracket with an annular structure, which surrounds the outside of the crankshaft rotor 21. The outer side of the mover bracket is movably connected to the linear guide shaft 24 through a linear bearing 25, so that the crankshaft mover 23 can reciprocate relative to the crankshaft rotor 21 in the axial direction. A mover magnetic array 27 is provided on the inner side of the mover bracket, and the mover magnetic array 27 is connected to the mover bracket through a mover core 26. In this embodiment, the mover magnetic array 27 adopts N40SH neodymium iron boron permanent magnet, the mover core 26 adopts HM-S4 soft magnetic composite material, and the mover bracket adopts 6010 aluminum alloy.

[0057] like Figure 6 and Figure 7 As shown: the spiral magnetic array 22 has 6 poles, and 3 pairs of 6 poles are arranged along the axial direction (of the crankshaft rotor 21) in a manner where the N poles and S poles are adjacent; each pole magnet is composed of 4 single magnets of the same polarity connected end to end in the circumferential direction; each single magnet is a spiral structure, and the spiral directions of two adjacent single magnets are opposite, and the other parameters are the same.

[0058] Correspondingly, two mover magnetic arrays 27 are provided, symmetrically distributed on both sides of the spiral magnetic array 22. The mover magnetic array 27 is a long strip structure, and each mover magnetic array 27 also has 6 poles, arranged axially in a manner that the N pole and the S pole are adjacent, and are respectively opposite to the positions of the poles in the spiral magnetic array 22.

[0059] The axial span PL of the single magnetic array in the spiral magnetic array 22 is the pole pitch, which corresponds to one-third of the total stroke in this embodiment; the spiral span SL is the total stroke, that is, the maximum stroke of the reciprocating movement of the crankshaft mover 23. Through the magnetic force between the spiral magnetic array 22 and the mover magnetic array 27, a linkage is formed between the unidirectional rotation of the crankshaft rotor 21 and the reciprocating translation of the crankshaft mover 23.

[0060] 3. Engine

[0061] In this embodiment, the engine 3 is a two-stroke free piston engine, including a cylinder body and a piston 31 movable in the cylinder body, one side of the piston 31 is a combustion chamber, and the other side is an oil and gas storage chamber. A spark plug 32 is provided on the cylinder body on the combustion chamber side. The cylinder body on the oil and gas storage chamber side is connected to the magnetic crankshaft module 2, and four connecting rods 5 are connected to the end face of the piston 31 on this side. The connecting rods 5 pass through the cylinder body of the engine 1 and the outer shell of the magnetic crankshaft module 2 and are connected to the crankshaft mover 23, so that the crankshaft mover 23 and the piston 31 can translate synchronously. The maximum stroke of the crankshaft mover 23 is equal to the stroke of the piston 31.

[0062] In this embodiment, taking into account factors such as cost and manufacturability, the outer shell of the magnetic crankshaft module 2 is made airtight, and no sealing is performed between the magnetic crankshaft module and the cylinder block of the engine 3. Therefore, the low-temperature fuel (oil-gas mixture) injected into the cylinder block of the engine 3 can enter the magnetic crankshaft module 2 through the pores such as the channel where the connecting rod 5 is located.

[0063] The side wall of the cylinder of the engine 3 is provided with an air inlet 33 and an air outlet 36, which are symmetrically distributed on both sides of the cylinder, and both are provided with a one-way valve. A venting groove 35 is provided at the inner end of the cylinder on one side of the oil and gas storage chamber, and an air passage 34 is provided on the inner wall of the cylinder to connect the air inlet 33 and the venting groove 35.

[0064] 2. Working Process

[0065] Starting process: the generator 1 is running in electric state, the motor rotor 13 drags the crankshaft rotor 21 to the rated speed, and at the same time, the crankshaft rotor 21 will also synchronously drag the engine 3 piston 31 to reciprocate at the same frequency through the crankshaft mover 23. After reaching the rated speed, the power supply of the generator 1 is disconnected, and the engine 3 is started to generate electricity.

[0066] Reference Figure 8 As shown, the power generation operation process of the power generation device of this embodiment is divided into the following stages:

[0067] 1) When the piston 31 moves to the top dead center TDC position, the spark plug 32 ignites, and the combustion chamber generates kinetic energy to push the piston 31 to move toward the bottom dead center BDC; during this period, the piston 31 drives the motor rotor 13 to rotate through the crankshaft mover 23 and the crankshaft rotor 21 in turn, driving the generator 1 to generate electricity externally;

[0068] 2) When the piston 31 moves from TDC to the position of the intake hole 33 and the exhaust hole 36, on the one hand, the exhaust gas after combustion in the combustion chamber is discharged outward under the action of the pressure difference; on the other hand, with the exhaust gas being discharged and the movement of the piston 31, the oil and gas mixture stored in the oil and gas storage chamber is pressed into the combustion chamber through the ventilation groove 35, the air passage 34 and the intake hole 33; during this period, the piston 31 continues to drive the motor rotor 13 to operate and generate electricity;

[0069] 3) After reaching the bottom dead center BDC, the piston 31 starts to move back in the opposite direction. At this time, relying on the kinetic energy stored in the crankshaft rotor 21, on the one hand, it continues to drive the motor rotor 13 to rotate, and on the other hand, it drives the piston 31 to move back to the top dead center TDC. During this period, the space of the oil and gas storage chamber expands, the pressure decreases, and the new oil and gas are driven by the pressure difference and injected into the oil and gas storage chamber from the outside through the air inlet 33 and the air channel 34;

[0070] 4) After the piston 31 moves to the top dead center TDC position, the oil-gas mixture in the combustion chamber is compressed again, and the spark plug 32 is ignited to enter the next cycle.

[0071] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0072] The present invention is not limited to the above-mentioned embodiments. Any obvious improvement, substitution or deformation that can be made by those skilled in the art without departing from the essential content of the present invention belongs to the protection scope of the present invention.

Claims

1. A free piston power generation device, characterized in that: include: A generator (1) having a motor rotor (13) disposed therein; The engine (3) is a free piston engine and has a piston (31) therein; The magnetic crankshaft module (2) is provided with: A crankshaft rotor (21) is connected to the motor rotor (13), rotates synchronously with the motor rotor (13), and has a spiral magnetic array (22) on its surface; A crankshaft mover (23) is connected to the piston (31) and moves synchronously with the piston (31), and a mover magnetic array (27) is provided on the crankshaft mover; The magnetic force between the spiral magnetic array (22) and the mover magnetic array (27) cooperates to enable the unidirectional rotation of the crankshaft rotor (21) and the reciprocating translation of the crankshaft mover (23) to be linked.

2. The free piston power generation device according to claim 1, characterized in that: The spiral magnetic array (22) is formed by axially arranging multi-pole magnetic poles in a manner that the N poles and the S poles are adjacent to each other, and each pole magnet is composed of four single magnets of the same polarity connected end to end in the circumferential direction, each single magnet is a spiral structure, and the spiral directions of two adjacent single magnets are opposite; The mover magnetic array (27) is a long strip structure, formed by axially arranging multi-pole magnetic poles in a manner where the N poles and the S poles are adjacent to each other. Two mover magnetic arrays (27) are provided, symmetrically distributed on both sides of the spiral magnetic array (22).

3. The free piston power generation device according to claim 2, characterized in that: The spiral magnetic array (22) and the mover magnetic array (27) have six poles.

4. The free piston power generation device according to claim 2, characterized in that: An iron core is provided on the inner side of the spiral magnetic array (22) and the inner side of the mover magnetic array (27), respectively. The iron core is made of HM-S4 soft magnetic composite material, and the spiral magnetic array (22) and the mover magnetic array (27) are made of N40SH neodymium iron boron permanent magnets.

5. The free piston power generation device according to claim 1, characterized in that: The crankshaft mover (23) comprises a mover bracket, which is an annular structure and surrounds the outer side of the crankshaft rotor (21); Both sides of the mover bracket are connected to the housing of the magnetic crankshaft module (2) through a linear guide shaft (24), and the linear guide shaft (24) is axially parallel to the crankshaft rotor (21); The mover magnetic array (27) is provided on the inner side of the mover bracket, and the mover magnetic array (27) is opposite to the spiral magnetic array (22).

6. The free piston power generation device according to claim 1, characterized in that: The crankshaft rotor (21) is coaxial with the motor rotor (13).

7. The free piston power generation device according to claim 1, characterized in that: The cylinder body of the engine (3) is connected to the outer shell of the magnetic crankshaft module (2); one side of the piston (31) in the cylinder body is a combustion chamber, and the other side is an oil and gas storage chamber; on one side of the oil and gas storage chamber, the piston (31) is connected to the crankshaft mover (23) through a plurality of connecting rods (5); a spark plug (32) is provided on one side of the combustion chamber; The cylinder side wall is provided with an air inlet (33) and an air outlet (36), which are symmetrically distributed on both sides of the cylinder, and both are provided with a one-way valve; a vent groove (35) is provided at the inner end of the cylinder on one side of the oil and gas storage chamber, and an air passage (34) is provided to connect the air inlet (33) and the vent groove (35).

8. The free piston power generation device according to claim 7, characterized in that: The inner cavity of the outer shell of the magnetic crankshaft module (2) is connected to the oil and gas storage chamber of the cylinder body of the engine (3), and the outer shell of the magnetic crankshaft module (2) is airtight relative to the outside.

9. The free piston power generation device according to claim 1, characterized in that: The stroke of the crankshaft mover (23) is equal to the stroke of the piston (31).

10. The free piston power generation device according to claim 1, characterized in that: The crankshaft rotor (21) is used to store kinetic energy to push the piston (31) back to the top dead center and to maintain the motor rotor (13) in operation during this period.

Images