CN218816684U - Double-rotor air-floating free piston Stirling generator with cooling center pillar - Google Patents

Abstract

The utility model discloses a double-rotor air-floating free piston Stirling generator of area cooling center pillar belongs to heat energy power technical field, and this Stirling generator has the structure innovation of three aspect for existing model: firstly, a T-shaped center pillar is arranged in an inner cavity of an ejector, a separation cavity formed by the ejector in a configuration matching mode is functionally provided with two gas springs with superposed rigidity, and a dynamic pressure phase is utilized to construct an air bearing; secondly, the air film surface of the air bearing of the power piston and the functional holes of the high-pressure air chamber and the low-pressure air chamber are respectively arranged on the inner wall and the outer wall of the power piston so as to inhibit the parasitic flow on the air bearing surface; thirdly, a cooling center pillar is arranged, and a cooling medium in the cooling center pillar can maintain the air gap of the mover to be stable in size. The whole machine has no wearing parts, the discharger does not depend on light noble metal materials, and the discharger can operate for a long time without maintenance at high temperature. The thermoelectric conversion device with high performance and high cost performance is provided for various scenes including severe environment applications such as aerospace-level nuclear power sources and unmanned underwater power cabin sections.

Description

Double-rotor air-floating free piston Stirling generator with cooling center pillar

Technical Field

The utility model relates to a heat energy power technology, concretely relates to double-mover air-floating free piston stirling generator of area cooling center pillar.

Background

The Stirling device uses Stirling cycle as a working principle and is a closed cycle machine working based on the temperature difference of a heat source. The use of the composition is divided into two categories: the Stirling engine adopts a forward Stirling cycle, working media in the device absorb heat at high temperature for expansion and carry out heat compression at normal temperature, and the obtained expansion work is greater than the compression work, so that the heat energy is converted into mechanical energy; the device which adopts reverse Stirling cycle is called as a Stirling refrigerator, mechanical energy is consumed by the device to realize heat release compression of working medium at normal temperature, and heat absorption expansion at low temperature generates a refrigeration effect. The transmission structure of the pressing element is divided into two categories: the mechanical Stirling is driven by a mechanism, and the motion phase and amplitude of the rotor are determined by the mechanism; the other type is free piston type Stirling, rigid mechanisms are not connected between the rotors, and the moving parts move back and forth under the restraint of gas force, inertia force and restoring force according to the dynamic law; the amplitude and the phase of the rotor can be changed along with different working condition parameters. The linear reciprocating motor is integrated inside the modern free piston type Stirling engine to improve the transmission efficiency, and oil-free lubrication, abrasion-free operation, long service life and high reliability are realized through the ways of plate spring support, air floatation or magnetic levitation and the like; the vibration and noise level is greatly reduced by an opposite mode or an additional vibration absorber; is superior to a mechanical Stirling machine in various indexes.

The Stirling device and an external heat source exchange heat in a partition wall mode, so that the Stirling device is suitable for various heat source types such as gas, liquid and solid fuels, medium-high temperature waste heat, solar photo-heat, nuclear reactor heat energy and the like. The working medium is usually helium, which is friendly to the environment. The generator is applied to the scenes of underwater power, space power, solar disc type power generation, a mobile generator, combined heat and power supply and the like, and the refrigerator is applied to the fields of infrared and superconducting device cooling, biological and medical refrigeration cold chains and the like.

At least two rotors are needed in the free piston type Stirling engine to realize the volume change of the expansion cavity and the compression cavity, so that the heat-work conversion effect is realized. The rotor with the end part close to the compression cavity is called a power piston or a compression piston, and the rotor with the end part close to the expansion cavity is called an ejector or a gas distribution piston; the reciprocating motion of the two rotors can drive working media to reciprocate between the expansion cavity and the compression cavity through the mutually adjacent heat exchanger, the heat regenerator and the cooler runner, and the pressure of the working media can undergo periodic variation out of synchronization with the rotors in the process, so that heat-power conversion is generated. If the two rotors work in respective resonance states, large amplitude can be obtained, high working cavity pressure amplitude is achieved, and stable working conditions are achieved under the restriction of internal damping and external loads.

In the design of the free piston stirling engine, in order to realize oil-free lubrication and abrasion-free operation of the mover, an implementation way of radial supporting force and axial restoring force of the mover needs to be defined. In a typical product representing the manufacturer Infinia corporation, the ejector and the power piston are disposed in two cylinders, one large and one small, each supported independently by a plate spring, as shown in fig. 17. The function of the leaf springs is to provide radial support of the mover while providing a suitable axial restoring force. The volumes of the gas in the back pressure cavity and the inner cavity of the discharger are periodically changed due to the oscillation of the rotor, and the gas is equivalent to a gas spring. In this type of ejector, there are 2 sets of leaf springs fixed to the center post inside, and the power piston is supported by the other two sets of leaf springs. A gas spring with a static volume V is arranged in the ejector, and gas in the back pressure cavity also has the function of the gas spring. The axial restoring force (also called stiffness) of the ejector is provided by the leaf spring and the gas spring V; the rigidity of the power piston comprises a plate spring, a back pressure cavity equivalent gas spring and the electromagnetic rigidity of the motor.

In another typical product, which represents the company Sunpower in the manufacturer, the ejector and the power piston operate coaxially in a cylinder of the same caliber, with a thin rod at the bottom of the ejector passing coaxially through the power piston and fixed at its end to the centre of a leaf spring located in the back pressure chamber. The leaf spring provides radial support and axial stiffness to the ejector. The axial stiffness of the power piston is provided by a gas spring of a back pressure cavity and the electromagnetic stiffness of a motor, the radial supporting force of the power piston is provided by a static pressure air bearing based on a one-way valve and arranged on the power piston, and the company patent US5525845 further discloses a scheme that the air bearing is combined with a plate spring for application.

Limited to the fatigue limit of elastic metal materials, the machine type using a plate spring and the one-way valve air bearing using an elastic air valve are difficult to operate all the year round under severe and unmanned scenes (such as space navigation, unmanned underwater vehicles and the like). US patent 5140905 by MTI corporation, usa, discloses a maintenance-free, long-life model of integrated gas spring, free of elastic elements, relying on a hole-and-groove structure to realize dual-rotor air flotation, as shown in fig. 18.

In the machine, the discharger consists of four parts, an upper gas spring cavity and a lower gas spring cavity are enclosed with peripheral structural parts, and a side gas spring cavity is communicated with the upper gas spring cavity through a gas circuit. The upper gas spring refers to a gas spring cavity close to the hot zone, and the lower gas spring refers to a gas spring cavity close to the compression cavity. The upper air spring cavity and the lower air spring cavity jointly provide axial rigidity for the reciprocating oscillation of the ejector; a hydrostatic bearing air storage chamber is arranged in the ejector component, a lower air spring cavity is used for periodic and pulse type air pumping of the air storage chamber, and an air floating effect is formed in an air gap through air injection small holes formed in the circumferential direction of the wall surface of the component, so that radial supporting force is provided for the ejector. In the aspect of a power piston, the machine type realizes periodic pulse type air pumping and pressure relief of high-pressure and low-pressure air chambers in the piston through hole and groove structures arranged on the wall surface of a cylinder and the wall surface of the piston. Specifically, as shown in fig. 19 and 20, when the fourth hole 138 meets the first hole 124, the first high-pressure chamber 122 is pulse-pumped, the gas in the first high-pressure chamber 122 is injected from the second hole 128 circumferentially arranged on the piston wall surface and then flows to the adjacent annular groove 134 along the air gap, and then enters the first low-pressure chamber 120 through the third hole 136 in the annular groove 134, and when the fifth hole 140 meets the annular groove 134, the first low-pressure chamber 120 is depressurized. Thus, an air floatation effect is formed in an air gap between the power piston and the air cylinder, and a radial supporting force is provided for the power piston; and the axial stiffness of the power piston is provided by the gas spring of the back pressure cavity and the electromagnetic stiffness of the motor.

The machine type with long service life, no maintenance, high power and high cost performance is the basis for expanding application scenes and enhancing the competitiveness of the free piston Stirling device with other technical schemes. In the existing machine type scheme, certain restriction factors limit the realization of high performance and high cost performance of the free piston Stirling, and the axial and radial support mode of the rotor has innovation space.

The model scheme shown in figure 17 reduces the manufacturing and assembling difficulty because the ejector group component and the power piston group component are not required to be strictly coaxial, and is suitable for manufacturing large-cylinder-diameter and large-power machines. However, the limitation of this machine type using a large number of plate springs is that: (1) Limited by the fatigue limit of the spring, limiting its use to requirements 10 ⁹ An application scenario with a period above; (2) From the dynamics perspective, in an oscillation system, the dead weight equivalent mass of the plate spring is combined into the mass of the rotor, and the way of increasing the running frequency of the machine by increasing the number of the plate springs is limited in engineering effect, so that the working conditions of high frequency and high power density are difficult to obtain; the gas spring in the ejector occupies a larger space due to the plate spring assembly, and the equivalent stiffness of the gas spring occupies a smaller proportion of the total stiffness.

The gas spring is limited by the working principle of the gas spring, only can provide axial rigidity, and cannot independently provide radial support for the rotor. Even if some technical approach is adopted to provide radial support for the ejector, the ejector of the type shown in fig. 17 can be made without using a plate spring set inside, thus allowing the possibility of a substantial reduction of the internal gas spring chamber volume V; however, the effective increase of the gas spring stiffness is also limited due to the following two reasons: (1) In order to obtain a commercially valuable performance index, the ratio of the center pillar diameter D1 to the ejector outer diameter D2 in FIG. 17 should not be too large, and the construction is general

The ratio of the area S1 corresponding to D1 to the volume V is in direct proportion to the rigidity of the gas spring, so that the lifting amplitude is limited; (2) The gas spring has relaxation loss, the larger the S1/V is, the larger the internal irreversible loss is, and the engineering isGenerally, the delta V/V is less than 0.1, and a gas spring with high efficiency and large rigidity cannot be obtained by simply reducing the volume V.

The main disadvantages of the model shown in fig. 18 are two aspects: (1) The axial dimension of the ejector structure is overlong, so that the total length of the machine is increased, the volume is increased, and the cost is increased greatly. In the version of fig. 17, the bottom surface of the ejector is adjacent to the bottom planebase:Sub>A-base:Sub>A of the cooler, whereas in the version of fig. 18, in order to realizebase:Sub>A double air spring and air bearing, the ejector member shown in the dashed box spans significantly the bottom plane B-B of the cooler, and the ejector part structure enclosing the upper air spring cavity with the structural member is massive, resulting in the same material being used, the ejector mass in the version of fig. 18 is significantly greater than that in the version of fig. 17. The MTI company selects expensive rare light metal pure beryllium to manufacture the discharger, and then the engineering index is realized. Besides pure beryllium, the engineering material with high temperature and high pressure resistance, good dimensional stability and extremely light density is rare, and the application of the machine type in aerospace scenes is limited. In addition, the large-volume side air spring is required to ensure the air floatation effect, so that the volume and the weight of the machine are further increased. (2) The hole-groove structure of the power piston air bearing has non-ideal parasitic working medium migration. When the machine is working, the first high-pressure air chamber 122 maintains the pressure at a quasi-static level above the pressure equalization and below the highest pressure of the first backpressure chamber 116, and the first low-pressure air chamber 120 maintains the pressure at a quasi-static level below the pressure equalization and above the lowest pressure of the first backpressure chamber 116; however, the pressure of the back pressure cavity fluctuates between the highest pressure and the lowest pressure periodically, and most of the time in the period, the pressure in the first back pressure cavity 116 is higher than the pressure in the first low pressure air chamber 120, so that the working medium of the back pressure cavity flows backwards into the first low pressure air chamber 120 through the fifth hole 140 and the third hole 136 in the annular groove 134, the pressure of the working medium is increased, and the bearing capacity of the air film is reduced. Moreover, the presence of the fourth hole 138 may also introduce a disturbance to the gas film by the first back pressure chamber 116, which affects the main flow direction and stability of the gas film.

As mentioned above, the implementation of radial support and axial stiffness of the two movers, the ejector and the power piston, is the core of a free piston type design, and essentially determines the lifetime, performance and cost of the machine. Through structural innovation, for active cell axial stiffness and radial support provide new solution, the drawback of avoiding current scheme is the utility model discloses a starting point.

From the viewpoint of dynamics, the gas spring does not generate additional mass for the rotor, and is a preferable way for constructing a large-stiffness structure and guaranteeing high-frequency operation, and the large-stiffness gas spring structure is required to be compact as much as possible so as to reduce the length of the ejector, thereby reducing the manufacturing cost of the ejector. A self-pumping air bearing is built in the machine to provide radial support for the rotor, and the self-pumping air bearing is also a preferred way for realizing no abrasion, long service life and high reliability. The air bearing configuration requires consideration of four factors: (1) A long and narrow air gap is needed, the width of the air gap is generally less than 0.02mm, air ejected from the small hole forms an air film in the long and narrow air gap and generates an air floatation effect on the rotor, the supporting force of the air film and the air consumption of the air floatation are very sensitive to the change of the width of the air gap, and if structural measures can be adopted to ensure the stability of the width of the air gap and inhibit the temperature effect from a cold state to a hot state, the structure is very beneficial; (2) The air chamber is constructed, the high-pressure air chamber and the low-pressure air chamber with the pressure in a quasi-static level are a path by designing a hole-groove structure, and if the reuse of some functional cavities (such as a compression cavity, an air spring cavity and the like) in the machine can be realized by structural innovation, the structural complexity of the air bearing can be obviously reduced, and the rotor is lighter; (3) The structure and the gas circuit are reasonably arranged, and parasitic flow generated when the air bearing works is inhibited as much as possible; (4) The periodic stability and the reliability of the air bearing are reflected in that measures are needed to inhibit the circumferential pulsation of the rotor during axial oscillation and prevent the directional migration of working media between the cavities.

Based on the above thought, the utility model realizes (1) the high-rigidity discharger gas spring with compact structure in principle through the structural innovation of three aspects; (2) Parasitic flow on the bearing surface of the rotor air bearing is inhibited; (3) And the size of the air gap between the ejector and the power piston is kept stable. The machine type has no moving wear, elastic parts which are easy to fatigue failure and ejectors, does not depend on light noble metal materials, can stably run at high temperature throughout the year and is free of maintenance; high performance, cost effective thermoelectric conversion device solutions are provided for a number of application scenarios.

SUMMERY OF THE UTILITY MODEL

First, the present invention creatively provides a new configuration inside an ejector, as shown in fig. 21, an ejector assembly typically comprises three bodies, i.e., an upper body, a middle body and a lower body, including a cylinder coaxial with the inside and the outside and a cylinder fixed to the inner wall of the outer cylinder through a partition, wherein the cylinder is newly added, the newly added structural member matched with the cylinder is called a T-shaped center cylinder, in order to simplify the positional relationship and the movement air gap relationship between the ejector and other components in the present solution, the outer cylinder of the ejector is called the outer wall of the ejector for short, the inner cylinder of the ejector is called the inner wall of the ejector for short, C1 denotes the movement air gap between the cylinder and the T-shaped center cylinder, C2 denotes the movement air gap between the inner wall of the ejector and the cooling center cylinder or the upper cylinder sleeve, and C3 denotes the movement air gap between the outer wall of the ejector and the main cylinder sleeve.

As shown in fig. 22, inside the new configuration ejector, the T-shaped center pillar and the associated structural member divide the internal volume into two chambers, the volumes of which are respectively filled with different types of dots as V1 and V2, and since the T-shaped center pillar is a static structural member, when the ejector reciprocates, the two chambers V1 and V2 are equivalent to two gas springs, which are respectively called a gas spring chamber one and a gas spring chamber two. The outer diameter of the T-shaped center pillar is D3, the diameter of the outer wall of the ejector is D2, the aperture of the inner wall of the ejector is D1, the corresponding moving air gaps are C1, C3 and C2 in the figure 21 respectively, and the rigidity of V1 is in direct proportion to that of V1

The stiffness of V2 is proportional to ^>

Because the pressure phases are opposite, the rigidity is superposed; when the configuration is applied, the value of the outer diameter D3 of the T-shaped center pillar can be obviously larger than that of D1, and is not restricted by the proportion between D1 and D2, so that a loose parameter condition is provided to obtain large rigidity; furthermore, the ejector is compact and the entire ejector does not cross the cooler bottom plane C-C. The large rigidity and compact configuration can enable the ejector made of conventional materials to operate under high-frequency working conditions, and does not depend on rare light materials.

How does the new configuration ejector achieve radial support? The ejector should be as light as possible, and if a separate air chamber is provided, the weight of the mover is inevitably increased, and the structural complexity is also increased. From the foregoing elemental analysis of the construction of the air bearing, it can be seen that the presence of three long and narrow moving air gaps C1, C2, and C3 in the new configuration provides the basic conditions for constructing the air bearing. The utility model discloses an analysis to the inside cavity pressure phase place of machine realizes the multiplexing in function chamber through the structure innovation.

Specifically, the method comprises the following steps:

(1) FIG. 23 is a diagram of a free piston Stirling heat engine mover displacement and compression cavity pressure vector under a typical working condition. X _d Is an ejector displacement vector, X _p As a power piston displacement vector, P _c Is the compression chamber pressure vector. In the new configuration, the pressure vector P in the gas spring chamber V2 ₂ And ejector displacement vector X _d Have the same phase.

(2) FIG. 24 shows Pc and P within a cycle under typical conditions ₂ Characteristic points of amplitude variation. During the period of the cycle time period a-b, the second air spring cavity can release pressure to the compression cavity; during the adjacent cycle time periods b-c, the compression chamber may be vented to the gas spring chamber two, and so on. By combining the characteristics with a new configuration, two pairs of compression cavities of the air spring cavity are decompressed directly by small hole throttling injection circumferentially arranged on the circumferential surface of the inner wall of the discharger, an air floatation air film is formed in a moving air gap C2 in a period from a to b, and radial support is formed on the discharger; and in the b-C time period, the pressure relief of the compression cavity to the air spring cavity II needs to construct a pressure guiding flow channel, a throttling small hole and a converging slot hole structure on the circumference of the outer wall of the discharger, an air floatation air film is formed in the moving air gap C3, and radial support is formed for the discharger.

(3) FIG. 25 is a graph illustrating the change in pressure amplitude of gas spring chamber one and gas spring chamber two over a cycle. Structural features based on new configurations, P ₁ And P ₂ The phases are 180 degrees apart. By arranging small injection holes respectively communicated with the first gas spring cavity and the second gas spring cavity in the circumferential direction of the T-shaped center column or the first ejector cylinder, an air floatation air film with alternately changed flow direction half period can be formed in the moving air gap C1, and radial support is formed for the ejector.

(4) By comprehensively adopting the two structures, the alternate and partial time period superposition enhanced air floatation effect can be formed in the three long and narrow moving air gaps C1, C2 and C3, and the poor air floatation effect of the air floatation bearing when the pressure difference between the associated cavities is small is avoided. As shown in fig. 24, the air flotation effect is weak in C2 and C3 near the characteristic points a, b and C, and strong in C1; thereby ensuring that the ejector with the new configuration can obtain enough radial supporting force at any time of the cycle. The air floatation effect is realized by reusing the existing air spring cavity of the novel mechanism without additionally constructing an air storage chamber. When the air bearing works, only trace gas is needed, and the function cavity with large volume is not obviously influenced.

In the second aspect, since the air bearing is sensitive to the variation of the air gap width, theoretically, the air bearing is cubic, and the air gap width is too wide or too narrow, which leads to air bearing failure. Under the existing technical scheme, along with the heat diffusion effect of heating at the hot end of the machine, air gaps at all positions in the machine can be changed to different degrees. If the size change of the air gap position along with the temperature can be inhibited as much as possible, the operation reliability and the air floatation stability of the machine type can be improved. The utility model discloses creative proposal cooling center pillar structure, the coolant that flows in it can maintain cooling center pillar, T type center pillar air gap temperature at a little more than coolant temperature level. The cooperative cooler can maintain the temperatures of three moving air gaps C1, C2 and C3 of the ejector with a new structure to be slightly higher than the temperature level of a cooling medium, and the moving air gap at the inner side of the power piston matched with the cooling center column is also at the temperature level of the cooling medium, so that the phenomenon that the rotor is blocked or air-floated to lose efficacy when the rotor runs for a long time at a high temperature can be avoided, and the specific structure is illustrated in the attached drawings below.

Furthermore, in the aspect of the radial support measure of the power piston, aiming at the defect of parasitic flow in the patent scheme of the MTI power piston static pressure air-float bearing, the utility model configures the outer cylindrical wall surface of the rotor piston into an air-float bearing surface, only sets a gas orifice and a confluence slotted hole, and enables the air film functional zone in the motion air gap between the power piston and the cylinder to always keep fixed flow direction and no parasitic disturbance; on the inner cylindrical surface of the power piston, air inlet holes and air vent holes are arranged at large intervals, and in a long and narrow air gap which is obviously lengthened, air leakage among the chambers is greatly inhibited, and the specific structure is described in the following figures.

In addition, when the free piston Stirling device operates, the problem that the leakage amount along the moving air gap is asymmetric in half period, so that the center of the rotor is induced to drift can occur. A common method known in the art is the "mid-point deflation method", i.e. the provision of air passages to let the associated chambers experience a short, sufficient pressure equalization in the region of the center point of oscillation of the mover. In the ejector of the new configuration, pressure equalizing holes are preferably provided in the T-shaped center pillar and the ejector-first cylinder, and the specific configuration will be described below with reference to the drawings.

Finally, in a machine type without the constraint of the plate spring, technical measures for stabilizing the circumferential angle of the rotor are needed, and failure is prevented when holes in the rotor are intersected with holes in a static structural component, such as the intersection of the holes in the rotor and the holes in the structural component in pressure equalizing, air pumping, pressure relief processes and the like. By utilizing the inherent characteristics of like-polarity repulsion and unlike-polarity attraction of the magnetic poles of the magnets, the magnetic suspension assembly is constructed at a proper position on the rotor and the structural member, so that the circumferential position can be prevented from generating obvious angular pulsation. A typical magnetic suspension structure is shown in fig. 26, in which opposite polarity magnets are arranged in pairs along the circumferential direction on two parts which need to be kept fixed at relative angles. In the novel type machine, two rotors need to restrict circumferential positions in axial movement, a magnetic suspension assembly needs to be preferably arranged in a suitable area which is allowed by an installation space and has relatively low temperature, and in order to ensure a restriction effect, the length of a magnet along the axial direction of the rotors is larger than the amplitude of the rotors. The specific structure is illustrated in the accompanying drawings.

A double-rotor air-floating free piston Stirling generator with a cooling center column comprises an outer shell, a hot head, a hot end heat exchanger, a heat regenerator, a cooler, an ejector, a power piston, a main cylinder sleeve, a T-shaped center column, the cooling center column, a partition column and a linear motor assembly, wherein the outer shell, the hot head and the cooling center column form a closed cavity, the ejector is arranged in the hot head, an expansion cavity is formed between the ejector and the hot head heat exchanger, the hot end heat exchanger, the heat regenerator and the cooler are sequentially arranged in an annular flow channel between the hot head and the ejector, the main cylinder sleeve is arranged in the outer shell and fixedly connected with the outer shell, a moving air gap exists between the outer wall of the ejector and the inner wall of the main cylinder sleeve, and a moving air gap exists between the inner wall and the cooling center column or the main cylinder sleeve, the cooling device comprises a main cylinder sleeve, a power piston, a discharger, a cooling center column and a main cylinder sleeve, wherein the power piston is arranged between the main cylinder sleeve and the cooling center column, a movement air gap is formed between the outer wall of the power piston and the inner wall of the main cylinder sleeve, a movement air gap is formed between the inner wall of the power piston and the cooling center column, a compression cavity is defined by the power piston, the discharger, the cooling center column and the main cylinder sleeve, a first vent hole for communicating the compression cavity with a cooler flow channel is uniformly arranged on the main cylinder sleeve along the circumferential direction, a partition column is arranged at the bottom in the cooling center column, a gas cavity is formed between the partition column and the cooling center column, a back pressure cavity is defined by the power piston, an outer shell and the cooling center column, a second vent hole for communicating the back pressure cavity with the gas cavity is uniformly arranged on the lower portion of the cooling center column along the circumferential direction, and the gas cavity is a component of the volume of the back pressure cavity; the T-shaped center pillar is arranged in the ejector and fixedly connected with the top of the cooling center pillar or the top of the main cylinder sleeve, the ejector comprises a first cylinder, the first cylinder is fixed in the middle of the ejector through a partition plate, a moving air gap is formed between the inner wall of the first cylinder and the outer wall of the T-shaped center pillar, an air spring cavity in the ejector is divided into an air spring cavity I and an air spring cavity II by the T-shaped center pillar and the cooling center pillar or between the T-shaped center pillar and the main cylinder sleeve, and a cavity formed by the interior of the partition pillar, the interior of the cooling center pillar, the bottom of the T-shaped center pillar or the interior of the partition pillar, the interior of the cooling center pillar, the bottom of the T-shaped center pillar and the upper portion of the main cylinder sleeve is used for circulating cooling media; the linear motor assembly is arranged between the outer shell and the main cylinder sleeve, and annular magnetic steel in the linear motor assembly is fixedly connected with the bottom of the power piston through a magnetic steel base.

Preferably, a moving air gap is formed between the inner wall of the ejector and the cooling center pillar, the air spring cavity in the ejector is divided into a first air spring cavity and a second air spring cavity by the T-shaped center pillar and the cooling center pillar, and a cavity defined by the interior of the partition pillar, the interior of the cooling center pillar and the bottom of the T-shaped center pillar is used for circulating a cooling medium; the air guide holes communicated with the compression cavity are uniformly formed in the bottom of the ejector along the circumference, the first air injection holes communicated with the air guide holes are uniformly formed in the outer wall of the ejector along the circumference, the first annular confluence groove is further formed in the outer wall of the ejector, the first air inlet holes communicated with the second air spring cavity are uniformly formed in the first annular confluence groove, the second air injection holes are uniformly formed in the inner wall of the ejector along the circumference, and when the pressure of the compression cavity is greater than the pressure of the second air spring cavity, the first air injection holes throttle air injection to form an air floatation effect in a moving air gap between the ejector and a main cylinder sleeve; and when the pressure of the second air spring cavity is greater than that of the compression cavity, the second air injection hole throttles and injects air to form an air floatation effect in a moving air gap between the ejector and the cooling center pillar, the air floatation effect provides radial support for the reciprocating motion of the ejector, and the outer diameter of the T-shaped center pillar is greater than that of the cooling center pillar.

Preferably, the main cylinder sleeve comprises an upper cylinder sleeve and a lower cylinder sleeve, the upper cylinder sleeve and the lower cylinder sleeve are both fixedly connected with the outer shell, the upper cylinder sleeve comprises an inner cylinder and an outer cylinder which are connected through a bottom plate, a moving air gap is formed between the inner wall of the ejector and the outer wall of the inner cylinder, a moving air gap is formed between the outer wall of the ejector and the inner wall of the outer cylinder, an air spring cavity in the ejector is divided into an air spring cavity I and an air spring cavity II by a T-shaped middle column and the upper cylinder sleeve, the bottom of the upper cylinder sleeve is fixedly and hermetically connected with the top of the cooling middle column, a cavity defined by the interior of a partition column, the interior of the cooling middle column, the bottom of the T-shaped middle column and the upper cylinder sleeve is used for circulating a cooling medium, a moving air gap is formed between the inner wall of the lower cylinder sleeve and the outer wall of the power piston, a vent hole III is formed in the bottom plate of the upper cylinder sleeve and is used for communicating a compression cavity divided by the bottom plate, and the vent hole I is arranged at the bottom of the outer cylinder; the air guide holes communicated with the compression cavity are uniformly formed in the bottom of the ejector along the circumference, the first air injection holes communicated with the air guide holes are uniformly formed in the outer wall of the ejector along the circumference, the first annular confluence groove is further formed in the outer wall of the ejector, the first air inlet holes communicated with the second air spring cavity are uniformly formed in the first annular confluence groove, the second air injection holes are uniformly formed in the inner wall of the ejector along the circumference, and when the pressure of the compression cavity is greater than the pressure of the second air spring cavity, the first air injection holes throttle air injection to form an air floatation effect in a moving air gap between the ejector and the outer cylinder outer wall; when the pressure of the second air spring cavity is higher than that of the compression cavity, the second air injection hole throttles and injects air to form an air floatation effect in a moving air gap between the ejector and the outer wall of the inner cylinder, and the air floatation effect provides radial support for the ejector to reciprocate; the outer diameter of the T-shaped center pillar is larger than that of the inner cylinder.

Preferably, the upper cylinder sleeve and the lower cylinder sleeve can adopt cylinder sleeves with different diameters.

Preferably, as for the technical scheme, the air gap width of the moving air gap formed between the inner wall of the first cylinder and the outer wall of the T-shaped center post is less than 0.02mm, and the length of the moving air gap is more than 4 times of the unilateral stroke of the ejector.

Preferably, the outer wall of the first cylinder or the inner wall of the first cylinder is uniformly provided with jet holes along the circumferential direction, the jet hole communicated with the first gas spring cavity is a third jet hole, the jet hole communicated with the second gas spring cavity is a fourth jet hole, and when the pressure of the first gas spring cavity is higher than that of the second gas spring cavity, the jet holes jet air in three stages, so that an air floatation effect is formed in a moving air gap between the inner wall of the first cylinder and the outer wall of the first cylinder; when the pressure of the second air spring cavity is higher than that of the first air spring cavity, the fourth air injection hole throttles and injects air, an air floatation effect is formed in a moving air gap between the inner wall of the first cylinder and the outer wall of the T-shaped center pillar, and the air floatation effect provides radial support for the reciprocating motion of the ejector.

Preferably, in the above technical solution, the distance between the third air injection hole and the fourth air injection hole is more than twice of the single-side stroke of the ejector.

Preferably, the power piston comprises a high-pressure air chamber and a pneumatic air chamber, the outer wall of the power piston is uniformly provided with a fifth air injection hole communicated with the high-pressure air chamber along the circumferential direction, the outer wall of the power piston is further provided with a second annular converging groove, a second air inlet hole communicated with the low-pressure air chamber of the power piston is uniformly arranged in the second annular converging groove, the side wall of the cooling center column, which forms the air chamber with the partition column, is uniformly provided with an upper air pumping hole and a lower pressure relief hole along the circumferential direction, the inner wall of the power piston is further uniformly provided with a third air inlet hole and a fourth air vent along the circumferential direction, the third air inlet hole is matched with the upper air pumping hole and is used for communicating the high-pressure air chamber and the back pressure chamber, the fourth air vent is matched with the lower pressure relief hole and is used for communicating the low-pressure air chamber and the back pressure chamber, and during five-joint air injection of the air injection hole, an air flotation effect is formed in a movement air gap between the outer wall of the power piston and the inner wall of the main cylinder sleeve, so as to provide radial support for the reciprocating movement of the power piston.

Preferably, in the above technical solution, a distance between the upper pump air hole and the third air inlet hole is smaller than a unilateral stroke of the power piston, a distance between the lower pressure relief hole and the fourth air vent hole is smaller than a unilateral stroke of the power piston, the third air inlet hole is closer to the T-shaped center pillar than the upper pump air hole, and the lower pressure relief hole is closer to the T-shaped center pillar than the fourth air vent hole.

Preferably, the T-shaped center pillar and the first cylinder are provided with a first pressure equalizing hole for instantly communicating the first gas spring cavity and the second gas spring cavity.

Preferably, the power piston and the main cylinder sleeve are provided with a second pressure equalizing hole for instantly communicating the compression cavity and the back pressure cavity.

Preferably, a magnetic suspension base body is fixed at the bottom in the outer shell, and first magnets which are matched with each other for use are uniformly fixed on the magnetic steel base and the magnetic suspension base body along the circumferential direction respectively.

Preferably, the T-shaped center pillar and the ejector inner wall are respectively and uniformly fixed with a second magnet along the circumferential direction, wherein the second magnets are mutually matched and used.

The beneficial effects of the utility model reside in that:

1. the T-shaped center pillar is arranged to divide the gas spring cavity in the discharger into a first gas spring cavity and a second gas spring cavity, the diameter design value range of the T-shaped center pillar is wide, and low loss and high rigidity can be achieved loosely. Compared with the existing scheme, the weight of the discharger can be greatly reduced, the discharger does not depend on rare light materials, and the production and processing cost is greatly saved.

2. The ejector air bearing scheme realizes the multiplexing of a functional cavity, so that a cavity does not need to be additionally opened up, the ejector is simple and light in structure, and the working condition of high frequency and large amplitude is easier to realize.

3. The cooling middle column is arranged, so that the ejector, the power piston and the dynamic sealing area of the upper cylinder sleeve are effectively cooled, the temperature effect of high-temperature thermal diffusion on the size of a moving air gap is inhibited, and the amplitude attenuation of the rotor, the air floatation failure and the clamping of the rotor are prevented when the machine works for a long time.

4. The air film surface of the air bearing of the rotor piston and the air chamber inlet and outlet holes are respectively arranged on the inner cylindrical surface and the outer cylindrical surface, so that the stable flow direction of gas in the air film is ensured, and parasitic flow is inhibited.

5. In the model scheme that the main cylinder sleeve is divided into the upper cylinder sleeve and the lower cylinder sleeve, the caliber of the whole machine is reduced because the lower cylinder sleeve is smaller than the caliber of the upper cylinder sleeve, so that the method is suitable for application scenes sensitive to the calibers; and the cooling center pillar is shortened, the upper cylinder sleeve and the lower cylinder sleeve do not need strict coaxiality, and the manufacturing cost and the assembly difficulty are reduced.

6. The pressure-equalizing and magnetic suspension structure for preventing the center drift and circumferential pulsation of the rotor is comprehensively arranged in the machine, so that the operational reliability of the gas spring and the air bearing is structurally ensured.

The beneficial effects make the utility model discloses the model type can adapt to the requirement of harsh environment non-maintaining operation throughout the year and manufacturing cost has more the model type and has showing the advantage.

Drawings

FIG. 1 is a cross-sectional view of an embodiment.

FIG. 2 is a schematic view of a portion of the outer wall of the ejector and the main cylinder sleeve when the air-float effect is formed according to the first embodiment.

FIG. 3 is a schematic diagram illustrating a portion of an exemplary embodiment of an ejector wall and a cooling pillar in which an air-floating effect is generated.

Fig. 4 is a schematic structural diagram of the first pressure equalizing hole during action.

Fig. 5 is a schematic structural view of a portion of the power piston low-pressure air chamber when the power piston moves away from the direction of the back pressure chamber and the power piston low-pressure air chamber releases pressure to the back pressure chamber through the vent hole in the first embodiment.

FIG. 6 is a partial schematic structural view showing the back pressure chamber inflating the high pressure air chamber of the power piston through the pump air hole when the power piston moves towards the back pressure chamber in the first embodiment.

Fig. 7 is a schematic structural diagram of the second equalizing hole during the action.

Fig. 8 and 9 are schematic views of a T-shaped center pillar structure.

Fig. 10 and 11 are schematic structural views of the power piston.

Fig. 12 is a schematic view of a cooling center pillar structure.

Figure 13 is a cross-sectional view of the power piston magnetic suspension.

FIG. 14 is a cross-sectional view of the second embodiment.

FIG. 15 is a schematic view of a part of the structure of the ejector in the second embodiment when the air-floating effect is formed between the first cylinder and the T-shaped center pillar.

Fig. 16 is a cross-sectional view of the upper cylinder liner.

Fig. 17, 18, 19 and 20 are views of the prior art in the background art.

Fig. 21 is a cross-sectional view of the ejector.

FIG. 22 is a schematic diagram of the ejector gas spring chamber being subdivided.

Fig. 23 is a free piston stirling heat engine mover displacement and compression cavity pressure vector diagram.

FIG. 24 shows Pc and P in a cycle under typical conditions ₂ Amplitude variation graph.

FIG. 25 is a graph of the change in pressure amplitude of gas spring chamber one and gas spring chamber two during a cycle.

FIG. 26 is a schematic view of a typical magnetic suspension configuration.

The reference numbers are as follows: 1-outer shell, 2-hot head, 3-hot end heat exchanger, 4-heat regenerator, 5-cooler, 6-discharger, 601-cylinder I, 7-power piston, 8-main cylinder sleeve, 801-upper cylinder sleeve, 801 a-inner cylinder, 801 b-outer cylinder, 802-lower cylinder sleeve, 9-T type center column, 10-cooling center column, 11-isolating column, 12-linear motor component, 13-expansion chamber, 14-compression chamber, 15-vent hole I, 16-gas chamber, 17-back pressure chamber, 18-vent hole II, 19-clapboard, 20-gas spring chamber, 2001-gas spring chamber I, 2002-gas spring chamber II, 21-magnetic steel base, 22-gas guide hole, 23-gas spray hole I, 24-annular confluence groove I25-air inlet hole I, 26-air vent hole II, 27-bottom plate, 28-air vent hole III, 29-air vent hole III, 30-air vent hole IV, 31-high pressure air chamber, 32-air vent hole V, 33-annular confluence groove II, 34-low pressure air chamber, 35-air inlet hole II, 36-upper pumping air hole, 37-lower pressure relief hole, 38-air inlet hole III, 39-air vent hole IV, 40-pressure equalizing hole I, 41-pressure equalizing hole II, 42-magnetic suspension base body, 43-first magnet, 44-second magnet, 45-air vent hole VI, 116-back pressure cavity I, 120-low pressure air chamber I, 122-high pressure air chamber I, 124-first hole, 128-second hole, 134-annular groove, 136-third hole, 138-fourth hole, 140-five holes.

Detailed Description

The technical solution of the present invention is clearly and completely described below with reference to the accompanying drawings of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

Example one

The double-rotor air-floating free piston stirling generator with the cooling center column as shown in fig. 1 to 13 comprises an outer shell 1, a thermal head 2, a hot end heat exchanger 3, a heat regenerator 4, a cooler 5, an ejector 6, a power piston 7, a main cylinder sleeve 8, a T-shaped center column 9, a cooling center column 10, a partition column 11 and a linear motor assembly 12, wherein the outer shell 1, the thermal head 2 and the cooling center column 10 form a closed cavity, the ejector 6 is arranged in the thermal head 2 and forms an expansion cavity 13 with the thermal head 2 and the hot end heat exchanger 3, the heat regenerator 4 and the cooler 5 are sequentially arranged in an annular flow channel between the thermal head 2 and the ejector 6, the main cylinder sleeve 8 is arranged in the outer shell 1 and fixedly connected with the outer shell 1, a moving air gap exists between the outer wall of the ejector 6 and the main cylinder sleeve 8, a moving air gap exists between the inner wall and the cooling center column 10, the cooling device comprises a power piston 7, a main cylinder sleeve 8, a cooling center column 10, an ejector 6, a cooling center column 10 and a main cylinder sleeve 8, wherein the power piston 7 is arranged between the main cylinder sleeve 8 and the cooling center column 10, a moving air gap is formed between the outer wall of the power piston 7 and the inner wall of the main cylinder sleeve 8, a moving air gap is formed between the inner wall and the cooling center column 10, the power piston 7, the ejector 6, the cooling center column 10 and the main cylinder sleeve 8 enclose a compression cavity 14, a first vent hole 15 for communicating the compression cavity 14 with a flow channel of the cooler 5 is uniformly arranged in the circumferential direction of the main cylinder sleeve 8, a partition column 11 is arranged at the bottom in the cooling center column 10, a gas chamber 16 is formed between the partition column 11 and the cooling center column 10, a back pressure cavity 17 is enclosed by the power piston 7, an outer shell 1 and the cooling center column 10, a second vent hole 18 for communicating the back pressure cavity 17 with the gas chamber 16 is uniformly arranged in the circumferential direction of the lower portion of the cooling center column 10, and the gas chamber 16 is a constituent part of the volume of the back pressure cavity 17; the T-shaped center pillar 9 is arranged in the ejector 6 and fixedly connected with the top of the cooling center pillar 10, the ejector 6 comprises a first cylinder 601, the first cylinder 601 is fixed in the middle of the ejector 6 through a partition plate 19, a moving air gap exists between the inner wall of the first cylinder 601 and the outer wall of the T-shaped center pillar 9, an air spring cavity 20 in the ejector 6 is divided into an air spring cavity I2001 and an air spring cavity II 2002 by the T-shaped center pillar 9 and the cooling center pillar 10, and a cavity defined by the interior of the partition pillar 11, the interior of the cooling center pillar 10 and the bottom of the T-shaped center pillar 9 is used for circulating a cooling medium; the linear motor assembly 12 is arranged between the outer shell 1 and the main cylinder sleeve 8, and annular magnetic steel in the linear motor assembly 12 is fixedly connected with the bottom of the power piston 7 through a magnetic steel base 21.

In this embodiment, the bottom of the ejector 6 is uniformly provided with air vents 22 communicated with the compression cavity 14 along the circumference, the outer wall of the ejector 6 is uniformly provided with a first air vent 23 communicated with the air vents 22 along the circumference, the outer wall of the ejector 6 is also provided with a first annular confluence groove 24, a first air inlet 25 communicated with the second gas spring cavity 2002 is uniformly arranged in the first annular confluence groove 24, the inner wall of the ejector 6 is uniformly provided with a second air vent 26 along the circumference, when the pressure of the compression cavity 14 is greater than the pressure of the second gas spring cavity 2002, the first air vent 23 throttles and injects air, and an air floatation effect is formed in a moving air gap between the ejector 6 and the main cylinder sleeve 8; when the pressure of the second air spring cavity 2002 is higher than that of the compression cavity 14, the second air injection hole 26 throttles and injects air to form an air floatation effect in a moving air gap between the ejector 6 and the cooling center pillar 10, the air floatation effect provides radial support for the reciprocating motion of the ejector 6, and the outer diameter of the T-shaped center pillar 9 is larger than that of the cooling center pillar 10.

In the embodiment, the air gap width of the moving air gap formed between the inner wall of the cylinder 601 and the outer wall of the T-shaped center pillar 9 is less than 0.02mm, and the length of the moving air gap is more than 4 times of the single-side stroke of the ejector 6.

In this embodiment, the outer wall of the T-shaped center pillar 9 or the inner wall of the first cylinder 601 is uniformly provided with air injection holes along the circumferential direction, the air injection hole communicated with the first air spring cavity 2001 is an air injection hole III 29, the air injection hole communicated with the second air spring cavity 2002 is an air injection hole IV 30, when the pressure of the first air spring cavity 2001 is greater than the pressure of the second air spring cavity 2002, the air injection hole III 29 throttles air injection, and an air floatation effect is formed in a moving air gap between the inner wall of the first cylinder 601 and the outer wall of the T-shaped center pillar 9; when the pressure of the second gas spring cavity 2002 is higher than the pressure of the first gas spring cavity 2001, the fourth gas injection hole 30 throttles and injects gas, so that an air floatation effect is formed in a moving air gap between the inner wall of the first cylinder 601 and the outer wall of the T-shaped center pillar 9, and the air floatation effect provides radial support for the reciprocating motion of the ejector 6.

In this embodiment, the distance between the third 29 and fourth 30 orifices is greater than twice the single-side stroke of the ejector 6.

In this embodiment, the outer wall of the power piston 7 is uniformly provided with a fifth air vent 32 communicated with the high-pressure air chamber 31 along the circumferential direction, the outer wall of the power piston 7 is further provided with a second annular confluence groove 33, a second air inlet 35 communicated with the low-pressure air chamber 34 of the power piston 7 is uniformly arranged in the second annular confluence groove 33, the side wall of the cooling center pillar 10 forming the air chamber 16 with the partition pillar 11 is uniformly provided with an upper pump air hole 36 and a lower pressure relief hole 37 along the circumferential direction, the inner wall of the power piston 7 is further uniformly provided with a third air inlet 38 and a fourth air vent 39 along the circumferential direction, the third air inlet 38 and the upper pump air hole 36 are matched to communicate the high-pressure air chamber 31 and the back pressure cavity 17, the fourth air vent 39 and the lower pressure relief hole 37 are matched to communicate the low-pressure air chamber 34 and the back pressure cavity 17, and during throttling of the fifth air vent 32, an air floating effect is formed in a moving air gap between the outer wall of the power piston 7 and the inner wall of the main cylinder sleeve 8, so as to provide radial support for the reciprocating motion of the power piston 7. In order to further enhance the air flotation effect, a jet head six 45 communicated with the high-pressure air chamber 31 can be arranged on the inner wall of the power piston 7.

In this embodiment, the distance between the upper pumping hole 36 and the third intake hole 38 is smaller than the single-side stroke of the power piston 7, the distance between the lower pressure relief hole 37 and the fourth vent hole 39 is smaller than the single-side stroke of the power piston 7, the third intake hole 38 is closer to the T-shaped center pillar 9 than the upper pumping hole 36, and the lower pressure relief hole 37 is closer to the T-shaped center pillar 9 than the fourth vent hole 39.

In this embodiment, the T-shaped center pillar 9 and the first cylinder 601 are provided with a first pressure equalizing hole 40 for instantly communicating the first gas spring cavity 2001 and the second gas spring cavity 2002.

In this embodiment, the power piston 7 and the main cylinder sleeve 8 are provided with a second pressure equalizing hole 41 for instantly communicating the compression chamber 14 with the back pressure chamber 17.

In this embodiment, a magnetic suspension base 42 is fixed at the bottom in the outer casing 1, and first magnets 43 used in cooperation with each other are uniformly fixed on the magnetic steel base 21 and the magnetic suspension base 42 along the circumferential direction, respectively.

In the present embodiment, the T-shaped center pillar 9 and the inner wall of the ejector 6 are respectively and uniformly fixed with the magnets 44 of the second number, which are used in cooperation with each other, along the circumferential direction.

The working principle of the Stirling generator follows the Stirling cycle thermal power conversion process, the ejector 6 and the power piston 7 move relatively, so that the volumes of the expansion cavity 13, the compression cavity 14 and the back pressure cavity 17 change periodically, the PV work generated by the expansion cavity 13 is larger than the PV work consumed by the compression cavity, and the electric energy can be output through the linear reciprocating motor. The linear reciprocating motor is of the prior art and will not be described in detail herein. The utility model discloses a main innovation point lies in adopting new construction to realize radial support, the axial stiffness to two active cells of ejector 6 and power piston 7. Under the control of the fluid law, under the action of the internal and external pressure difference, the gas in the closed cavity with the moving surface can generate pressure opposite to the moving direction on the moving surface and the rigidity characteristic similar to a spring, namely the gas spring effect. The air film in the long and narrow air gap of the jet source has the characteristic of resisting external force to reduce the width of the air gap within a certain load range, and presents radial rigidity, namely static pressure air flotation effect.

The ejector gas spring with high rigidity is realized through the T-shaped center pillar and the first cylinder 601, and when the ejector 6 and the power piston 7 move, a high-reliable air floatation effect can be formed between the ejector 6 and the main cylinder sleeve 8 and the cooling center pillar 10 or between the ejector 6 and the main cylinder sleeve 8 or between the ejector and the T-shaped center pillar 9, the power piston 7 and the main cylinder sleeve 8, zero friction is realized, and the service life of the whole machine is greatly prolonged.

The principle of radial support of the ejectors 6 is as follows: in the period, the pressure change of the lower air spring cavity II 2002 is ahead of the pressure change of the compression cavity 14, when the period is in a period a-b, the working medium is sprayed into a moving air gap between the ejector 6 and the cooling center pillar 10 through the second air injection hole 26 and flows into the compression cavity 14 through the moving air gap, when the period is in a period b-c, the working medium enters the first air injection hole 23 through the air guide hole 22, the working medium is sprayed into the moving air gap between the ejector 6 and the main cylinder sleeve 8, flows along the moving air gap, flows into the annular confluence groove I24, and flows back into the air spring cavity II 2002 through the first air inlet hole 25.

The complementary and strengthened air flotation process is that when the pressure of the first air spring cavity 2001 rises and the pressure of the second air spring cavity 2002 falls, the third air injection hole 29 injects a small amount of air in the first air spring cavity 2001, the small amount of air flows through a moving air gap formed between the inner wall of the first cylinder 601 and the outer wall of the T-shaped center post 9 and enters the second air spring cavity 2002, and in a symmetrical second half period, the fourth air injection hole 30 injects a small amount of air in the second air spring cavity 2002 and flows back to the first air spring cavity 2001 along the moving air gap. As can be seen from fig. 24 and 25, due to the symmetry of the pressure difference, it is not mandatory to achieve the air floating process that the dynamic pressure amplitudes in the compression chamber 14, the first gas spring chamber 2001, and the second gas spring chamber 2002 are equal.

The principle of the radial support of the power piston 7 is as follows: when the power piston 7 moves towards the back pressure cavity 17, the back pressure cavity 17 is compressed and the pressure is raised, when the upper pumping hole 36 and the air inlet hole three 38 meet, the working medium in the gas cavity 16 enters the high pressure air chamber 31 of the power piston 7 along the upper pumping hole 36 and the air inlet hole three 38, because the pressure difference exists between the high pressure air chamber 31 and the low pressure air chamber 34, the working medium is sprayed into a moving air gap between the power piston 7 and the main cylinder sleeve 8 through the five gas spraying holes 32, flows along the air gap, converges into the annular confluence groove two 33, and then enters the low pressure air chamber 34 through the air inlet hole two 35; when the power piston 7 moves away from the back pressure cavity 17, the back pressure cavity 17 is depressurized due to volume expansion, and when the lower pressure relief hole 37 meets the vent hole four 39, the working medium in the low pressure air chamber 34 enters the gas chamber 16 along the vent hole four 39 and the lower pressure relief hole 37, and flows back to the back pressure cavity 17. Under reasonably matched hole, groove, air chamber and moving air gap parameters, the high-pressure air chamber 31 and the low-pressure air chamber 34 can maintain a quasi-static pressure working condition, directional flow from the fifth gas injection hole 32 to the second confluence groove 33 always exists in the air film, and in each period, the air quantity consumed by pumping the back pressure cavity 17 to the high-pressure air chamber 31 can be compensated by the pressure relief process of the low-pressure air chamber 34 to the back pressure cavity 17. Because the air flow participating in the air film flow only accounts for a small part of the air flow of the high-pressure air chamber and the low-pressure air chamber, the high-pressure air chamber and the low-pressure air chamber only fluctuate slightly on the respective pressure level, and the quasi-steady-state characteristic is presented.

The first pressure equalizing hole 40 is used for enabling working media in the first gas spring cavity 2001 and the second gas spring cavity 2002 to be subjected to a short and sufficient pressure equalizing flow process through the first pressure equalizing hole 40 when pressure deviation occurs at the oscillation midpoint position of the ejector 6 due to the pressure of the first gas spring cavity 2001 and the pressure of the second gas spring cavity 2002, and therefore pressure deviation accumulation is restrained.

The second pressure equalizing hole 41 has the function that when pressure deviation occurs in the middle point position of oscillation of the power piston 7 in the compression cavity 14 and the back pressure cavity 17, the working medium in the compression cavity 14 and the back pressure cavity 17 can be subjected to a short and sufficient pressure equalizing flow process through the second pressure equalizing hole 41, and therefore pressure deviation accumulation is restrained.

The first magnet 43 and the second magnet 44 are used for preventing the ejector 6 and the power piston 7 from generating circumferential pulsation, so that each air hole is correspondingly aligned, and the air bearing is prevented from being damaged due to dislocation of the corresponding air hole, and the air floatation effect is prevented from being invalid.

The low-pressure air chamber 34 of the power piston 7 in this embodiment includes two parts that are communicated with each other vertically, and correspondingly, two annular confluence grooves 33 are provided on the outer wall of the power piston 7, and the annular confluence grooves 33 are symmetrically provided relative to the circumferentially provided five gas injection holes 32.

Example two

As shown in fig. 14 to 16, the second embodiment differs from the first embodiment in that the main cylinder liner 8 in this embodiment includes an upper cylinder liner 801 and a lower cylinder liner 802 both fixedly connected to the outer casing, the upper cylinder liner 801 includes an inner cylinder 801a and an outer cylinder 801b connected by a bottom plate 27, a moving air gap exists between the inner wall of the ejector 6 and the outer wall of the inner cylinder 801a, a moving air gap exists between the outer wall of the ejector 6 and the inner wall of the outer cylinder 801b, the air spring chamber 20 inside the ejector 6 is divided into an air spring chamber one 2001 and an air spring chamber two 2002 by the T-shaped center pillar 9 and the upper cylinder liner 801, the bottom of the upper cylinder liner 801 is fixedly and hermetically connected to the top of the cooling center pillar 10, the inside of the spacer pillar 11, the inside of the cooling center pillar 10, the bottom of the T-shaped center pillar 9 and the cavity surrounded by the upper cylinder liner 801 are used for circulating a cooling medium, a moving air gap exists between the inner wall of the lower cylinder liner 802 and the outer wall of the power piston 7, a vent hole three 28 is opened on the bottom plate 27 for communicating with the compression chamber 14 separated by the center pillar 27, and a vent hole 801b is opened on the bottom of the outer cylinder 801; air guide holes 22 communicated with the compression cavity 14 are uniformly formed in the bottom of the discharger 6 along the circumference, a first air injection hole 23 communicated with the air guide holes 22 is uniformly formed in the outer wall of the discharger 6 along the circumference, a first annular confluence groove 24 is further formed in the outer wall of the discharger 6, a first air inlet hole 25 communicated with the second air spring cavity 2002 is uniformly formed in the first annular confluence groove 24, a second air injection hole 26 is uniformly formed in the inner wall of the discharger 6 along the circumference, when the pressure of the compression cavity 14 is greater than the pressure of the second air spring cavity 2002, the first air injection hole 23 conducts throttling air injection, and an air floatation effect is formed in a moving air gap between the discharger 6 and the outer wall of the outer cylinder 801 b; when the pressure of the second air spring cavity 2002 is higher than that of the compression cavity 14, the second air injection hole 26 throttles and injects air, an air floatation effect is formed in a moving air gap between the ejector 6 and the outer wall of the inner cylinder 801a, and the air floatation effect provides radial support for the reciprocating motion of the ejector 6; the T-shaped center pillar 9 has an outer diameter larger than that of the inner cylinder 801 a. The upper cylinder sleeve 801 and the lower cylinder sleeve 802 can adopt cylinder sleeves with different diameters, preferably, the diameter of the upper cylinder sleeve 801 is large, the diameter of the lower cylinder sleeve 802 is small, the caliber of the whole machine can be reduced, and the cooling device is suitable for a scene sensitive to the caliber.

The working principle of the radial support of the ejector 6 and the power piston 7 is the same as in the previous example, except that the structural cylinder sleeve 801 replaces the part of the previous example between the compression chamber of the cooling center pillar 10 and the T-shaped center pillar 9.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (13)

1. The utility model provides a double-mover air supporting free piston stirling generator of area cooling center pillar which characterized in that: the high-pressure gas back-pressure cooling device comprises an outer shell, a hot head, a hot end heat exchanger, a heat regenerator, a cooler, an ejector, a power piston, a main cylinder sleeve, a T-shaped center pillar, a cooling center pillar, a partition pillar and a linear motor assembly, wherein the outer shell, the hot head and the cooling center pillar form a closed cavity, the ejector is arranged inside the hot head and forms an expansion cavity with the hot head and the hot end heat exchanger, the heat regenerator and the cooler are sequentially arranged in an annular flow passage between the hot head and the ejector, the main cylinder is sleeved in the outer shell and fixedly connected with the outer shell, a moving air gap is formed between the outer wall of the ejector and the inner wall of the main cylinder sleeve, a moving air gap is formed between the inner wall and the cooling center pillar or the main cylinder sleeve, the power piston is arranged between the main cylinder sleeve and the cooling center pillar, a moving air gap is formed between the outer wall of the power piston and the inner wall of the main cylinder sleeve, the cooling center pillar and the cooling center pillar form a compression cavity, the main cylinder sleeve is uniformly provided with a back-pressure cavity and a back-pressure cavity, and the back-pressure cavity are uniformly formed by gas back-pressure cavities; the T-shaped center pillar is arranged in the ejector and fixedly connected with the top of the cooling center pillar or the top of the main cylinder sleeve, the ejector comprises a first cylinder, the first cylinder is fixed in the middle of the ejector through a partition plate, a moving air gap is formed between the inner wall of the first cylinder and the outer wall of the T-shaped center pillar, an air spring cavity in the ejector is divided into an air spring cavity I and an air spring cavity II by the T-shaped center pillar and the cooling center pillar or between the T-shaped center pillar and the main cylinder sleeve, and a cavity formed by the interior of the partition pillar, the interior of the cooling center pillar, the bottom of the T-shaped center pillar or the interior of the partition pillar, the interior of the cooling center pillar, the bottom of the T-shaped center pillar and the upper portion of the main cylinder sleeve is used for circulating cooling media; the linear motor assembly is arranged between the outer shell and the main cylinder sleeve, and annular magnetic steel in the linear motor assembly is fixedly connected with the bottom of the power piston through a magnetic steel base.

2. A stirling generator in accordance with claim 1, wherein: a moving air gap is formed between the inner wall of the ejector and the cooling center pillar, an air spring cavity in the ejector is divided into an air spring cavity I and an air spring cavity II by the T-shaped center pillar and the cooling center pillar, and a cavity formed by the interior of the partition pillar, the interior of the cooling center pillar and the bottom of the T-shaped center pillar is used for circulating a cooling medium; the air guide holes communicated with the compression cavity are uniformly formed in the bottom of the ejector along the circumference, the first air injection holes communicated with the air guide holes are uniformly formed in the outer wall of the ejector along the circumference, the first annular confluence groove is further formed in the outer wall of the ejector, the first air inlet holes communicated with the second air spring cavity are uniformly formed in the first annular confluence groove, the second air injection holes are uniformly formed in the inner wall of the ejector along the circumference, and when the pressure of the compression cavity is greater than the pressure of the second air spring cavity, the first air injection holes throttle air injection to form an air floatation effect in a moving air gap between the ejector and a main cylinder sleeve; and when the pressure of the second air spring cavity is greater than that of the compression cavity, the second air injection hole throttles and injects air to form an air floatation effect in a moving air gap between the ejector and the cooling center pillar, the air floatation effect provides radial support for the reciprocating motion of the ejector, and the outer diameter of the T-shaped center pillar is greater than that of the cooling center pillar.

3. A stirling generator in accordance with claim 1, wherein: the main cylinder sleeve comprises an upper cylinder sleeve and a lower cylinder sleeve, the upper cylinder sleeve and the lower cylinder sleeve are fixedly connected with the outer shell, the upper cylinder sleeve comprises an inner cylinder and an outer cylinder which are connected through a bottom plate, a movement air gap is formed between the inner wall of the discharger and the outer wall of the inner cylinder, a movement air gap is formed between the outer wall of the discharger and the inner wall of the outer cylinder, an air spring cavity in the discharger is divided into an air spring cavity I and an air spring cavity II by a T-shaped middle column and the upper cylinder sleeve, the bottom of the upper cylinder sleeve is fixedly and hermetically connected with the top of the cooling center pillar, a cavity surrounded by the interior of the partition pillar, the interior of the cooling center pillar, the bottom of the T-shaped center pillar and the upper cylinder sleeve is used for circulating cooling media, a moving air gap exists between the inner wall of the lower cylinder sleeve and the outer wall of the power piston, a third vent hole is formed in the bottom plate of the upper cylinder sleeve and used for communicating a compression cavity partitioned by the bottom plate, and the first vent hole is formed in the bottom of the outer cylinder; the air guide holes communicated with the compression cavity are uniformly formed in the bottom of the ejector along the circumference, the first air injection holes communicated with the air guide holes are uniformly formed in the outer wall of the ejector along the circumference, the first annular confluence groove is further formed in the outer wall of the ejector, the first air inlet holes communicated with the second air spring cavity are uniformly formed in the first annular confluence groove, the second air injection holes are uniformly formed in the inner wall of the ejector along the circumference, and when the pressure of the compression cavity is greater than the pressure of the second air spring cavity, the first air injection holes throttle air injection to form an air floatation effect in a moving air gap between the ejector and the outer cylinder outer wall; when the pressure of the second air spring cavity is higher than that of the compression cavity, the second air injection hole throttles and injects air, an air flotation effect is formed in a moving air gap between the ejector and the outer wall of the inner cylinder, and the air flotation effect provides radial support for the reciprocating motion of the ejector; the outer diameter of the T-shaped center pillar is larger than that of the inner cylinder.

4. A stirling generator in accordance with claim 3, wherein: the upper cylinder sleeve and the lower cylinder sleeve can adopt cylinder sleeves with different diameters.

5. A stirling generator in accordance with claim 1, wherein: the air gap width of a moving air gap formed between the inner wall of the first cylinder and the outer wall of the T-shaped center pillar is smaller than 0.02mm, and the length of the moving air gap is larger than 4 times of the unilateral stroke of the ejector.

6. A stirling generator in accordance with claim 1, wherein: the outer wall of the T-shaped center pillar or the inner wall of the first cylinder is uniformly provided with jet holes along the circumferential direction, the jet hole communicated with the first gas spring cavity is a jet hole III, the jet hole communicated with the second gas spring cavity is a jet hole IV, and when the pressure of the first gas spring cavity is higher than that of the second gas spring cavity, the jet holes jet air in three stages, so that an air floatation effect is formed in a moving air gap between the inner wall of the first cylinder and the outer wall of the T-shaped center pillar; when the pressure of the second air spring cavity is higher than that of the first air spring cavity, the fourth air injection hole throttles and injects air, an air floatation effect is formed in a moving air gap between the inner wall of the first cylinder and the outer wall of the T-shaped center pillar, and the air floatation effect provides radial support for the reciprocating motion of the ejector.

7. A Stirling generator according to claim 6, wherein: and the distance between the third air injection hole and the fourth air injection hole is more than twice of the unilateral stroke of the discharger.

8. A Stirling generator according to any one of claims 1 to 7, wherein: the power piston is internally provided with a high-pressure air chamber and a low-pressure air chamber, the outer wall of the power piston is uniformly provided with a fifth air jetting hole communicated with the high-pressure air chamber along the circumferential direction, the outer wall of the power piston is further provided with a second annular converging groove, a second air inlet hole communicated with the low-pressure air chamber of the power piston is uniformly arranged in the second annular converging groove, the side wall of a gas chamber formed by the cooling center column and the partition column is uniformly provided with an upper air pumping hole and a lower pressure relief hole along the circumferential direction, the inner wall of the power piston is further uniformly provided with a third air inlet hole and a fourth air vent hole along the circumferential direction, the third air inlet hole is matched with the upper air pumping hole and is used for communicating the high-pressure air chamber and a back pressure chamber, the fourth air vent hole is matched with the lower pressure relief hole and is used for communicating the low-pressure air chamber and the back pressure chamber, and during five-throttling of the air jetting, an air flotation effect is formed in a moving air gap between the outer wall of the power piston and the inner wall of the main cylinder sleeve, so as to provide radial support for the reciprocating motion of the power piston.

9. A stirling generator in accordance with claim 8, wherein: the distance between the upper pump air hole and the air inlet hole III is smaller than the unilateral stroke of the power piston, the distance between the lower pressure relief hole and the vent hole IV is smaller than the unilateral stroke of the power piston, the air inlet hole III is closer to the T-shaped center pillar than the upper pump air hole, and the lower pressure relief hole is closer to the T-shaped center pillar than the vent hole IV.

10. A stirling generator according to claim 1, wherein: and a first pressure equalizing hole for instantly communicating the first gas spring cavity and the second gas spring cavity is formed in the T-shaped middle column and the first cylinder.

11. A stirling generator according to claim 1, wherein: and a second pressure equalizing hole for instantly communicating the compression cavity with the back pressure cavity is formed in the power piston and the main cylinder sleeve.

12. A stirling generator according to claim 1, wherein: the bottom is fixed with the magnetism and hangs the base member in the shell body, evenly be fixed with a magnet that mutually supports and use along circumference respectively on magnet steel base and the magnetism hang the base member.

13. A stirling generator in accordance with claim 1, wherein: and second magnets which are matched with each other for use are uniformly fixed on the inner walls of the T-shaped center column and the ejector along the circumferential direction respectively.

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