Frictionless design of a high-pressure circulating thermopump

Abstract

A thermopump comprises a sealed casing divided into a main casing volume and one or more secondary volumes. A thermopump comprises a rod. A thermopump comprises a displacer coupled to the rod, which oscillates to generate a pressure rise between a high-pressure phase and a low-pressure phase. A thermopump comprises one or more displacer rings, wherein the displacer rings are made of a material with thermal properties below a threshold. A thermopump comprises an insert, wherein the insert is configured to form a circumference of the main casing volume, and wherein the insert is made of a material with thermal properties below a threshold. A thermopump comprises one or more bushings, wherein the one or more bushings separate the main casing volume from the one or more secondary volumes.A thermopump includes one or more gas bearings configured to prevent contact between the rod and the sealed housing.

Description

CROSS-REFERENCE TO A RELATED APPLICATION

[0001] This application claims the benefit, pursuant to 35 USC § 119(e), of U.S. Provisional Application Serial No. 63 / 411,115, filed September 29, 2022, which is incorporated by reference in its entirety into this application. TECHNICAL AREA

[0002] The present disclosure relates generally to thermal pump systems and, more particularly, to the frictionless operation of thermal pumps. BACKGROUND

[0003] Various types of bearings can be used to prevent rods from contacting the side of a housing. However, many of the bearings used are not suitable for operation in clean and / or high-pressure environments due to the need for lubrication or suitable pressure differentials. Operating conventional bearing systems in clean and / or high-pressure environments can significantly reduce component life due to excessive friction or other adverse conditions for component wear. Therefore, there is a need to find a solution that provides adequate rod stability and service life in a clean and / or high-pressure environment. OVERVIEW

[0004] In accordance with embodiments of the present disclosure, a thermal pump is disclosed. In embodiments, the thermal pump comprises a sealed housing, wherein the sealed housing is divided into a main housing volume and one or more secondary volumes. In embodiments, the thermal pump comprises a rod, wherein the rod is configured to be driven to cause the rod to oscillate linearly within the sealed housing. In embodiments, the thermal pump comprises a displacer, wherein the displacer is coupled to the rod and oscillates within the main housing volume as a result of oscillation of the rod, wherein the oscillation of the displacer creates a pressure increase between a high pressure phase and a low pressure phase.In embodiments, the thermal pump comprises one or more displacer rings, wherein the one or more displacer rings are coupled to the displacer and extend radially outward into the main housing volume, wherein the one or more displacer rings are made from a displacer ring material selected such that a thermal conductivity coefficient of the displacer rings and / or a thermal expansion coefficient of the displacer rings is below a threshold value. In embodiments, the thermal pump comprises an insert, wherein the insert is configured to form a perimeter of the main housing volume, wherein the insert is made from an insert material selected such that a thermal conductivity coefficient of the insert and / or a thermal expansion coefficient of the insert is below the threshold value, wherein the one or more displacer rings and the insert direct a gas through the displacer.In embodiments, the thermal pump comprises one or more bushings, wherein the one or more bushings separate the sealed housing into the main housing volume and the one or more secondary volumes. In embodiments, the thermal pump comprises one or more gas bearings configured to prevent contact between the rod and the sealed housing, wherein the one or more gas bearings are configured to operate based on the high-pressure phase and the low-pressure phase generated by pressure fluctuations caused by the vibration of the displacer.

[0005] In accordance with embodiments of the present disclosure, a system is disclosed. In embodiments, the system comprises a broadband plasma light source. In embodiments, the system comprises a thermal pump configured to supply pressurized gas to a broadband plasma light source. In embodiments, the thermal pump comprises a sealed housing, wherein the sealed housing is divided into a main housing volume and one or more secondary volumes. In embodiments, the thermal pump comprises a rod, wherein the rod is configured to be driven to cause the rod to oscillate linearly within the sealed housing.In embodiments, the thermal pump comprises a displacer, wherein the displacer is coupled to the rod and oscillates within the main housing volume as a result of the oscillation of the rod, wherein the oscillation of the displacer creates a pressure increase between a high-pressure phase and a low-pressure phase. In embodiments, the thermal pump comprises one or more displacer rings, wherein the one or more displacer rings are coupled to the displacer and extend radially outward into the main housing volume, wherein the one or more displacer rings are made of a displacer ring material selected such that a thermal conductivity coefficient of the displacer rings and / or a thermal expansion coefficient of the displacer rings is below a threshold value.In embodiments, the thermal pump comprises an insert, the insert configured to form a perimeter of the main housing volume, the insert made of an insert material selected such that a thermal conductivity coefficient of the insert and / or a thermal expansion coefficient of the insert is below the threshold, wherein the one or more displacer rings and the insert direct a gas through the displacer. In embodiments, the thermal pump comprises one or more bushings, the one or more bushings separating the sealed housing into the main housing volume and the one or more secondary volumes.In embodiments, the thermal pump comprises one or more gas bearings configured to prevent contact between the rod and the sealed housing, wherein the one or more gas bearings are configured to operate based on the high pressure phase and the low pressure phase generated by pressure fluctuations caused by the vibration of the displacer.

[0006] In accordance with embodiments of the present disclosure, a method of operating a thermal pump is disclosed. In embodiments, the method includes isolating one or more secondary volumes from a main housing volume by one or more bushings. In embodiments, the method oscillates a displacer coupled to a rod to vary a pressure within the main housing volume, wherein the thermal pump has a high-pressure phase and a low-pressure phase caused by the oscillation of the displacer. In embodiments, the method supplies at least a first portion of the high-pressure phase of the thermal pump to a broadband plasma light source. In embodiments, the method supplies at least a second portion of the high-pressure phase of the thermal pump to one or more gas bearings located in each of the one or more secondary volumes.In embodiments, the method prevents contact between the rod and a housing of the thermal pump by the one or more gas bearings.In embodiments of the method, a gas is passed through the displacer by means of one or more displacer rings and an insert within the thermal pump, wherein the gas passed through the displacer generates the high pressure phase of the thermal pump, wherein the one or more displacer rings are coupled to the rod and extend radially outward into the main housing volume, wherein the displacer rings are made of a displacer ring material selected such that a thermal conductivity coefficient of the displacer rings and / or a thermal expansion coefficient of the displacer rings is below a threshold value, wherein the insert is configured to form a periphery of the main housing volume, wherein the insert is made of an insert material selected such that a thermal conductivity coefficient of the insert and / or a thermal expansion coefficient of the insert is below the threshold value.

[0007] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not necessarily restrictive of the invention as claimed. The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the general description, serve to explain the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The numerous advantages of the disclosure may be better understood by those skilled in the art by reference to the accompanying figures. Fig. 1 is a schematic cross-sectional illustration of a thermal pump according to one or more embodiments of the present disclosure. Fig. 2 is a block diagram of a system according to one or more embodiments of the present disclosure. Fig. 3 is a flowchart of a method according to one or more embodiments of the present disclosure. DETAILED DESCRIPTION

[0009] Reference will now be made in detail to the disclosed subject matter illustrated in the accompanying drawings. The present disclosure has been particularly shown and described with reference to certain embodiments and their specific features. The embodiments shown herein are to be considered as illustrative rather than restrictive. It should be readily apparent to those skilled in the art that various changes and modifications in form and detail may be made without departing from the spirit and scope of the disclosure.

[0010] Prolonged operation of a piston and / or linear rod in a clean and sealed (e.g., pressurized) environment can cause problems. Typical solutions for pistons (e.g., in applications such as motors, piston pumps, etc.) include bearings (e.g., ball bearings) and / or bushings. The bearings and / or bushings may require active lubrication (e.g., with grease) to extend their service life and avoid problems caused by excessive friction. However, lubrication suitable for non-clean environments (e.g., grease) may not be suitable for use in clean environments. Therefore, bearings and / or bushings operating in a clean environment can use dry lubricants or no lubrication. However, the service life of bearings and / or bushings using dry lubricants or no lubrication can be significantly reduced.

[0011] In certain applications, magnetic bearings can be used for frictionless stabilization in clean environments. However, the applications of magnetic bearings are generally limited to rotational stabilization. Occasionally, magnetic bearings can be adapted for other applications, but adapting magnetic bearings for applications related to the stabilization of a linear rod can be extremely difficult.

[0012] Conventional piston rings (e.g., used to seal a piston and compensate for thermal expansion) can also cause problems when used with a thermal pump in a clean environment. Precision mechanical systems (there are no clean mechanical piston pumps) designed for operation in a clean environment typically use temperature stabilization to minimize expansion and consequently limit the clearances between moving components. Lubrication-free operation is also common, but this results in a reduction in service life that is not appropriate for certain applications. However, such temperature stabilization is not possible with thermal pumps due to the required temperature difference between the hot and cold sides of the sealed housing.Finally, the use of very clean, vacuum-compatible grease is not possible in the temperature range associated with thermopump operation. Therefore, conventional piston rings may be unsuitable for use in thermopumps.

[0013] The present disclosure discloses systems for operating a thermal pump in a clean, high-pressure environment with a significantly increased lifetime, particularly compared to the other techniques described herein. More specifically, this disclosure presents a thermal pump with frictionless linear rod operation in a clean, high-pressure environment. Such a thermal pump can be used in conjunction with a broadband plasma (BBP)-based flow-through light source. More generally, the thermal pump can be used with a plasmatron light source (e.g., a light source where the plasma is placed in a gas stream (e.g., a wind tunnel)).

[0014] With reference to the Fig. 1-2, embodiments of a frictionless thermal pump 100 for use in a clean high pressure environment are shown in accordance with one or more embodiments of the present disclosure.

[0015] Fig. Figure 1 is a schematic cross-sectional illustration of the thermal pump 100 according to one or more embodiments of the present disclosure. Possible embodiments of thermal pumps are disclosed in U.S. Patent No. 11,450,521, issued September 20, 2022, which is incorporated herein by reference.

[0016] In embodiments, the thermal pump 100 includes a displacer 102 within a sealed housing 104. The displacer 102 may be a body configured to move linearly (e.g., up and down) within the sealed housing 104. The displacer 102 may be designed to allow gas to flow through it, e.g., by incorporating channels. The displacer 102 may further include one or more channels (e.g., vertical channels). The channels may, for example, be designed to allow gases to flow through the channel when the thermal pump 100 is operating (e.g., when the displacer 102 is oscillating). The displacer 102 may combine two functions: it insulates the gas at the hot and cold ends of the sealed housing 104 and provides heat exchange with the gas flowing through it.To meet these requirements, the displacer 102 is often composed of multiple components, one of which may be a regenerator (not shown) (e.g., a relatively small part with high thermal conductivity and high heat capacity disposed in the core of the displacer 102), while the remainder of the displacer 102 may be made of a lightweight material with low thermal conductivity and low heat capacity. In embodiments, the regenerator may be made of a multi-layer copper braid. Additionally, the displacer 102 may be made of a material having a high coefficient of thermal expansion. Because the displacer 102 may have low thermal conductivity and capacity, as well as a high coefficient of thermal expansion, the displacer 102 may experience a relatively large thermal expansion during operation of the thermal pump 100. As a non-limiting example, the displacer 102 may be made of Teflon.In this way, the displacer 102 may include components with different thermal conductivities (e.g., the regenerator may have a high heat capacity and the rest of the displacer 102 may have a low heat capacity). It should be noted that for the purposes of this application, the displacer 102 is referred to as a whole and not with reference to the individual components.

[0017] The displacer 102 may be configured to move a gas between the hot and cold ends of the sealed housing 104. The movement of the gas between the hot and cold ends of the sealed housing 104 may cause a pressure increase between a high-pressure phase and a low-pressure phase.

[0018] In embodiments, the thermal pump 100 includes a sealed housing 104. The sealed housing 104 may enclose a main housing volume 106 through which the displacer 102 moves linearly. The sealed housing 104 may have a significant temperature differential on either side of the sealed housing 104 (e.g., the top of the sealed housing 104 may be very cold and the bottom of the sealed housing 104 may be very hot, or vice versa). The large temperature differential between the two sides of the sealed housing 104 may result in significant thermal expansion. Because the displacer 102, with its vibrations, does not create a large pressure drop, only low sealing and drive forces are required in the thermal pump 100.

[0019] In embodiments, the thermal pump 100 includes a rod 108. The displacer 102 may be coupled to the rod 108 such that linear movement of the rod 108 drives the displacer 102. Further, the rod 108 may be configured to be driven such that the thermal pump 100 can be maintained as a sealed system (e.g., the rod 108 remains within the sealed housing 104 during operation of the thermal pump 100). For example, the rod 108 may be magnetically driven. In this way, the rod 108 may be coupled to one or more magnets 110.

[0020] The magnets 110 may correspond to one or more magnetic drivers 112. The magnetic drivers 112 may be located outside the thermal pump 100 (e.g., outside the sealed housing 104) and move linearly. The magnets 110 coupled to the rod 108 may be attracted by the magnetic drivers 112 such that the rod 108 is displaced in a manner corresponding to the displacement of the magnetic drivers 112. The magnetic drivers 112 may cause a periodic movement of the rod 108 (and thus the coupled displacer 102). For example, the rod 108 may oscillate once per second.

[0021] In embodiments, the thermal pump 100 includes one or more displacer rings 114. Each displacer ring 114 may be directly connected to the displacer 102. The displacer rings 114 may extend further radially outward through the main housing volume 106. The displacer rings 114 may be made of low-expansion materials (e.g., materials whose size is not affected by temperature changes). Furthermore, the displacer rings 114 may be made of materials that exhibit both low-expansion and low-conductivity properties. For example, the displacer rings 114 may be made of materials that exhibit a low coefficient of thermal conductivity and / or a low coefficient of thermal expansion of the displacer rings, such as glass, machinable glass (e.g., MACOR), ceramic, or the like.To illustrate, MACOR has a thermal conductivity of 1.46 W / (K*m), compared to 15 W / (K*m) for stainless steel. Thus, the heat flow between the upper part of the main housing volume 106 and the lower part of the main housing volume 106, as well as the possibility of expansion of the displacer rings 114, can be significantly reduced when using materials such as machinable glass.

[0022] In this way, the displacer rings 114 can be manufactured with a diameter slightly smaller than the diameter of the main housing volume 106, since the diameter of the displacer rings 114 does not change significantly with temperature changes (e.g., the displacer rings 114 can be almost the same size as the main housing volume 106 without touching due to expansion). It should be noted that the thermal expansion of the rod 108 can be minimal due to the small diameter of the rod.

[0023] The displacer rings 114 can be arranged at various locations on the displacer 102. For example, the displacer rings 114 can be arranged so that they are located on one or more sides of the displacer 102 (e.g., above the displacer 102 or below the displacer 102). In another example, the displacer rings 114 can be arranged at locations along the displacer 102 (e.g., the displacer 102 consists of two or more individual pieces with one or more displacer rings 114 between them). Another example is that the displacer rings 114 can be arranged at one or more ends of the displacer 102.

[0024] In embodiments, the thermal pump 100 includes an insert 116. The insert 116 may be a hollow cylinder and fit concentrically within the sealed housing 104 (e.g., the insert forms a perimeter of the main housing volume 106). In this way, the displacer rings 114 may be configured to be slightly smaller than the insert 116 (e.g., the displacer rings 114 may be slightly smaller than the insert 116, rather than slightly smaller than the main housing volume 106). The insert 116 may be made of a material having a low coefficient of thermal conductivity and / or a low coefficient of thermal expansion. The insert 116 may be made of materials such as glass, machinable glass (e.g., MACOR), ceramic, or the like (the insert 116 may be made of the same material as the displacer rings 114, or of a different material than the displacer rings 114, for example).It is noted that the use of such an insert 116 is possible because there are no pressure differences between the areas in the main housing volume 106.

[0025] The insert 116, in addition to the displacer rings 114, can result in a stabilized gap 118 (e.g., a gap 118 that is not susceptible to significant expansion and / or contraction of materials because low-expansion materials were used for both sides). Furthermore, the insert 116, in addition to the displacer rings 114, can result in improved insulation of the thermal pump 100. Because both the insert 116 and the displacer rings 114 can be made of low-conductivity materials, heat flow between the high-temperature and low-temperature regions of the main housing volume 106 can be reduced, preventing heat from escaping from the thermal pump 100 through the sealed housing 104. Thus, the addition of the insert 116 and / or the displacer rings 114 can increase the efficiency and / or performance of the thermal pump 100.

[0026] Additionally, the displacer rings 114 and insert 116 can minimize a gap 118 between the two. Thus, vibration of the displacer 102 and the displacer rings 114 can force a gas to flow through the displacer 102 and exchange heat (e.g., the gas flows exclusively (or almost exclusively) through the channels of the displacer 102 rather than flowing around the displacer 102). Additionally, the displacer rings 114 can isolate a hot end of the thermal pump 100 from a cold end of the thermal pump 100. The radial expansion of the displacer rings 114 can compensate for the thermal expansion of the displacer 102 and other components of the thermal pump 100 between a cold end of the main housing volume 106 and a hot end of the main housing volume.

[0027] The material used for the displacer rings 114 and / or the insert 116 can be selected such that the thermal conductivity coefficient and / or the thermal expansion coefficient is below a threshold value. For example, the threshold value can be selected such that the expansion of the displacer rings 114 and / or the expansion of the insert 116 (e.g., expansion caused by temperature differences within the thermal pump 100) does not result in contact with a solid surface (e.g., friction is prevented). Similarly, the dimensions of the displacer rings 114 and / or the insert 116 can be selected based on the thermal conductivity coefficient and / or the thermal expansion coefficient to minimize expansion and maximize insulation of the thermal pump 100.

[0028] Efficient operation of the thermal pump 100 may rely on the gas flowing through the channels of the displacer 102 and thus through the regenerator (e.g., if the regenerator is implemented as a separate part) rather than around the displacer 102. Therefore, precise displacer rings 114 and / or inserts 116 may be used to minimize the gap 118. For example, a small gap 118 may result in almost all of the gas in the main housing volume 106 flowing through the channels of the displacer 102 rather than around the displacer 102.

[0029] In embodiments, the thermal pump 100 includes one or more secondary volumes 120 (e.g., the sealed housing 104 creates one or more secondary volumes 120 in addition to the main housing volume 106). For example, there may be a secondary volume 120 at the top of the thermal pump 100 and a secondary volume 120 at the bottom of the thermal pump 100. The secondary volumes 120 may be configured for linear movement of the rod 108 while the displacer 102 remains within the main housing volume 106.

[0030] In embodiments, the thermal pump 100 includes one or more gas bearings 122. For example, each secondary volume 120 may contain a gas bearing 122. The gas bearings 122 may be operated with the pressure increase generated by the thermal pump 100.

[0031] In embodiments, the thermal pump 100 includes one or more bushings 124. For example, each secondary volume 120 may be separated from the main housing volume 106 by a bushing 124. The bushings 124 may form a tight fit with the housing 104 and / or the rod 108. In this way, gases may be prevented from migrating between the main housing volume 106 and the secondary volumes 120. The bushings 124 may further subdivide (e.g., separate) the sealed housing 104 into the main housing volume 106 and the one or more secondary volumes 120.

[0032] In embodiments, the thermal pump 100 includes a high-pressure reservoir 126 and a low-pressure reservoir 128. The pressures of the high-pressure reservoir 126 and the low-pressure reservoir 128 may be caused by the pressure increase caused by the thermal pump 100. For example, the high-pressure reservoir 126 may be connected to a high-pressure point of the thermal pump 100, such as an output of the thermal pump 100. Another example is the low-pressure reservoir 128, which may be connected to a low-pressure point of the thermal pump 100, e.g., an input of the thermal pump 100. High-pressure gas may be supplied to the center of the gas bearing 122 (e.g., to form a thin layer of gas that prevents contact between the rod 108 and the sealed housing 104).

[0033] It should be noted that while the pressure in the main housing volume 106 fluctuates between a high-pressure phase and a low-pressure phase (e.g., the main housing volume 106 fluctuates between a high-pressure phase and a low-pressure phase), the pressure in the secondary volumes 120 may remain stable or constant (e.g., or nearly constant). The pressure in the secondary pressure volumes 120 may be kept constant due to the bushings 124. The bushings 124 may be configured to significantly reduce the gas flow between the main housing volume 106 and the secondary volumes 120 (e.g., by reducing the space in which gases can flow around the rod between the main housing volume 106 and the secondary volumes 120). Because gas is at high pressure in the secondary volume 120, the bushing 124 does not need to completely block the gas flow between the main housing volume 106 and the secondary volumes 120.Instead, the bushings 124 only need to form a precise opening and leave a small gap between the bushing 124 and the rod 108 (e.g., to prevent friction between the rod 108 and the bushing 124). Furthermore, it should be noted that the pressure drop can be up to the level of the pressure increase in the thermal pump 100, and the gas flow rate can be significantly lower than the flow rate of the thermal pump 100.

[0034] The gas bearings 122 can function by creating a layer of gas (e.g., high-pressure gas) between two surfaces (e.g., the rod 108 and the sealed housing 104). This layer of gas can prevent the two surfaces from contacting during linear displacement of the rod 108, allowing the rod 108 to operate in a frictionless environment (e.g., friction due to the gas may be negligible below a certain speed threshold). Because no lubrication is required (e.g., because there is no contact), the gas bearings 122 can also be used in a clean environment. The bushings 124 can also lead to stabilized pressures in the secondary volumes 120 (e.g., the volume in which the gas bearings 122 are located), which can make the gas bearings 122 suitable for operation in a high-pressure environment.

[0035] The high-pressure reservoir 126 and the low-pressure reservoir 128 can be used to operate the gas bearings 122 (e.g., the gas bearings 122 can operate using the pressure differential between the inlet of the thermopump 100 and the outlet of the thermopump 100). The gas flow required to operate the gas bearings 122 can be significantly lower than the gas flow generated by the thermopump 100, allowing the gas bearings 122 to operate (e.g., create a frictionless environment) while the thermopump 100 maintains its operational functions. The gas used in the thermopump 100 and for the gas bearings 122 can be any gas. For example, the gas can be argon (Ar).

[0036] Fig. 2 is a block diagram of a system 200 according to one or more embodiments of the present disclosure.

[0037] In embodiments, the system 200 includes the thermal pump 100.

[0038] In embodiments, the system 200 includes a broadband plasma (BBP) light source 202. However, it should be noted that the thermal pump 100 disclosed herein may be used with any device requiring the operation of a thermal pump 100. The thermal pump 100 may be configured to supply the BBP light source 202 with a pressurized gas. For example, the BBP light source 202 may be configured to operate partially on high-pressure gases. For example, the BBP light source 202 may require pressurized gases to operate a laser within the BBP light source 202. Therefore, the thermal pump 100 may supply such a pressurized gas to the BBP light source 202. Such a configuration is disclosed in U.S. Patent No. 11,450,521, issued September 20, 2022, which is already incorporated herein by reference.

[0039] Furthermore, the BBP light source 202 can be used for any purpose known in the art. For example, the BBP light source 202 can be used for metrology.

[0040] Fig. 3 is a flowchart of a method 300 according to one or more embodiments of the present disclosure. Applicant notes that the embodiments and enabling technologies previously described herein in connection with thermal pump 100 and / or system 200 should be construed to extend to method 300. However, it is further understood that method 300 is not limited to the architecture of thermal pump 100 and / or system 200.

[0041] In embodiments, method 300 includes a step 302 of isolating one or more secondary volumes from a main housing volume by one or more bushings. For example, the bushings may form a narrow opening around the rod that passes through the one or more secondary volumes and the main housing volume. Since the secondary volumes may be under high pressure and there may be little space for gas to escape between the bushing and the rod, the bushings may effectively isolate the one or more secondary volumes from the main housing volume.

[0042] In embodiments, the method 300 includes a step 304 of oscillating a displacer coupled to a rod to change a pressure within the main housing volume, wherein the thermal pump has a high pressure output caused by the oscillation of the displacer and a low pressure input.

[0043] In embodiments, method 300 includes a step 306 in which at least a first portion of the high-pressure output of the thermopump is supplied to a broadband plasma light source. For example, a large portion of the pressure increase generated by the oscillation of the displacer can be utilized by the broadband plasma light source.

[0044] In embodiments, method 300 includes a step 308 in which at least a second portion of the high-pressure output of the thermal pump is supplied to one or more gas reservoirs located in each of the one or more secondary volumes. For example, the second portion of the high-pressure output can be used by the gas reservoirs to create a thin gas film. Furthermore, the gas escaping from the thin film can be redirected into the low-pressure inlet of the thermal pump and repressurized.

[0045] In embodiments, method 300 includes a step 310 in which the one or more gas bearings prevent contact between the rod and a housing of the thermal pump. For example, the thin film of pressurized gas can be used to prevent contact between the rod and the housing. In this way, the thermal pump can operate without friction (e.g., negligible friction) between the rod and the housing.

[0046] In embodiments, the method 300 comprises a step 312 of directing a gas through the displacer by means of one or more displacer rings and an insert within the thermal pump, wherein the gas directed through the displacer creates the high pressure output of the thermal pump, wherein the one or more displacer rings are coupled to the rod and extend radially outward into the main housing volume, wherein the displacer rings are made of a displacer ring material selected such that a thermal conductivity coefficient and / or a thermal expansion coefficient of the displacer rings is below a threshold value, wherein the insert is configured to form a perimeter of the main housing volume, wherein the insert is made of an insert material selected such that a thermal conductivity coefficient and / or a thermal expansion coefficient of the insert is below the threshold value.For example, the displacer and insert can be configured to minimize a gap within the main housing volume, e.g., a gap between the displacer ring and the insert. Minimizing such a gap can lead to increased thermal pump performance, since almost all of the gas within the thermal pump flows through the displacer.

[0047] The subject matter described herein sometimes illustrates various components contained within or connected to other components. It should be understood that such illustrated architectures are merely exemplary, and that, in fact, many other architectures may be implemented that achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively "connected" such that the desired functionality is achieved. Therefore, two components combined herein to achieve a particular functionality may be considered "connected together" such that the desired functionality is achieved, regardless of architectures or intermediary components.Likewise, two components connected in this manner may be considered "connected" or "coupled" to achieve the desired functionality, and two components that can be connected in this manner may also be considered "coupleable" to achieve the desired functionality. Specific examples of "coupleable" include, but are not limited to, physically interacting and / or physically interacting components, wirelessly interacting and / or wirelessly interacting components, and / or logically interacting and / or logically interacting components.

[0048] It is believed that the present disclosure and many of the attendant advantages will be understood from the foregoing description, and it will be apparent that various changes in the form, construction, and arrangement of components may be made without departing from the disclosed subject matter or without sacrificing all of its essential advantages. The described form is merely illustrative, and it is the intent of the following claims to encompass and embrace such changes. Moreover, the invention is defined by the appended claims. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 63 / 411,115

[0001] US 11,450,521 [0015, 0038]

Claims

[1] Thermal pump, comprising: a sealed enclosure, the sealed enclosure being divided into a main enclosure volume and one or more secondary volumes; a rod, the rod being configured to be driven to cause the rod to oscillate linearly within the sealed housing; a displacer, the displacer being coupled to the rod and oscillating within the main housing volume as a result of the oscillation of the rod, the oscillation of the displacer producing a pressure increase between a high pressure phase and a low pressure phase; one or more displacer rings, wherein the one or more displacer rings are coupled to the displacer and extend radially outward into the main housing volume, wherein the one or more displacer rings are made of a displacer ring material selected such that a thermal conductivity coefficient of the displacer rings and / or a thermal expansion coefficient of the displacer rings is below a threshold value; an insert, the insert configured to form a perimeter of the main housing volume, the insert being made of an insert material selected such that a coefficient of thermal conductivity of the insert and / or a coefficient of thermal expansion of the insert is below the threshold, the one or more displacer rings and the insert directing a gas through the displacer; one or more bushings, the one or more bushings separating the sealed housing into the main housing volume and the one or more secondary volumes; and one or more gas bearings configured to prevent contact between the rod and the sealed housing, wherein the one or more gas bearings are configured to operate based on the high pressure phase and the low pressure phase generated by pressure fluctuations caused by the vibration of the displacer. [2] A thermal pump according to claim 1, wherein the rod comprises one or more magnets coupled to the rod. [3] The thermal pump of claim 2, wherein the rod is magnetically driven via one or more external magnetic drivers and the one or more magnets coupled to the rod. [4] A thermal pump according to claim 1, wherein the one or more secondary volumes remain at a constant pressure. [5] A thermal pump according to claim 1, wherein the main housing volume varies between two or more pressures. [6] Thermopump according to claim 1, wherein the insert and / or the one or more displacement rings are made of one of the following materials: glass, machinable glass or ceramic. [7] A thermal pump according to claim 1, wherein at least one of the one or more displacer rings is arranged at one or more ends of the displacer. [8] A thermal pump according to claim 1, wherein the displacer is formed from two or more individual parts. [9] A thermal pump according to claim 8, wherein at least one of the one or more displacer rings is arranged between the two or more individual parts of the displacer. [10] System comprising: a broadband plasma light source; and a thermal pump configured to supply the broadband plasma light source with compressed gas, the thermal pump comprising: a sealed enclosure, the sealed enclosure being divided into a main enclosure volume and one or more secondary volumes; a rod, the rod being configured to be driven to cause the rod to oscillate linearly within the sealed housing; a displacer, the displacer being coupled to the rod and oscillating within the main housing volume as a result of the oscillation of the rod, the oscillation of the displacer producing a pressure increase between a high pressure phase and a low pressure phase; one or more displacer rings, wherein the one or more displacer rings are coupled to the displacer and extend radially outward into the main housing volume, wherein the one or more displacer rings are made of a displacer ring material selected such that a thermal conductivity coefficient of the displacer rings and / or a thermal expansion coefficient of the displacer rings is below a threshold value; an insert, the insert configured to form a perimeter of the main housing volume, the insert being made of an insert material selected such that a coefficient of thermal conductivity of the insert and / or a coefficient of thermal expansion of the insert is below the threshold, the one or more displacer rings and the insert directing a gas through the displacer; one or more bushings, the one or more bushings separating the sealed housing into the main housing volume and the one or more secondary volumes; and one or more gas bearings configured to prevent contact between the rod and the sealed housing, wherein the one or more gas bearings are configured to operate based on the high pressure phase and the low pressure phase generated by pressure fluctuations caused by the vibration of the displacer. [11] A thermal pump according to claim 10, wherein the rod comprises one or more magnets coupled to the rod. [12] The thermal pump of claim 11, wherein the rod is magnetically driven via one or more external magnetic drivers and the one or more magnets coupled to the rod. [13] A thermal pump according to claim 10, wherein the one or more secondary volumes remain at a constant pressure. [14] A thermal pump according to claim 10, wherein the main housing volume varies between two or more pressures. [15] Thermal pump according to claim 10, wherein the insert and / or the one or more displacement rings are made of one of the following materials: glass, machinable glass or ceramic. [16] A thermal pump according to claim 10, wherein at least one of the one or more displacer rings is arranged at one or more ends of the displacer. [17] A thermal pump according to claim 10, wherein the displacer is formed from two or more individual parts. [18] A thermal pump according to claim 17, wherein at least one of the one or more displacer rings is arranged between the two or more individual parts of the displacer. [19] A method for operating a thermal pump, comprising: Isolating one or more secondary volumes from a main housing volume by one or more bushings; Oscillating a displacer coupled to a rod to vary a pressure within the main housing volume, the thermal pump having a high pressure phase and a low pressure phase caused by the oscillation of the displacer; feeding at least a first part of the high-pressure phase of the thermopump into a broadband plasma light source; Supplying at least a second portion of the high pressure phase of the thermopump to one or more gas reservoirs located in each of the one or more secondary volumes; Preventing contact between the rod and a housing of the thermal pump by the one or more gas bearings; Passing a gas through the displacer by means of one or more displacer rings and an insert within the thermal pump, wherein the gas passed through the displacer creates the high pressure phase of the thermal pump, wherein the one or more displacer rings are coupled to the rod and extend radially outward into the main housing volume, wherein the displacer rings are made of a displacer ring material selected such that a thermal conductivity coefficient of the displacer rings and / or a thermal expansion coefficient of the displacer rings is below a threshold value, wherein the insert is configured to form a periphery of the main housing volume, wherein the insert is made of an insert material selected such that a thermal conductivity coefficient of the insert or a thermal expansion coefficient of the insert is below the threshold value.

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