System comprising first linear flexible bearing

Abstract

A system includes a linear flexible bearing that includes an integral one-piece plate. The plate has a first portion, a second portion surrounding the first portion, and a flexure region between the first portion and the second portion. At least one of the first portion and the second portion is thicker than the deflection region.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 226,630, filed on July 28, 2021, and entitled “LINEAR FLEXURE BEARINGS HAVINGNON-UNIFORM THICKNESS, AND SYSTEMS AND METHODS FOR USING AND MAKING THE SAME,” which application is incorporated herein by reference in its entirety. Technical Field

[0003] The utility model relates to a system comprising a first linear flexure bearing (flexure bearing), and also relates to a system comprising a linear flexure bearing assembly. Background Art

[0004] Linear flexible bearings reduce or eliminate wear and friction of seals between parts that move linearly relative to each other, such as between a piston and a piston housing. The present disclosure relates to new flexible bearings, systems using such flexible bearings, and methods of using and making such flexible bearings and systems. Utility Model Content

[0005] This section summarizes some features of the utility model. Other features may be described in subsequent sections. The utility model is defined by the appended claims, which are incorporated into this section by reference.

[0006] A system is provided, including a first linear flexible bearing, the first linear flexible bearing including an integral one-piece plate. The plate has a first portion, a second portion surrounding the first portion, and a flexing region between the first portion and the second portion. At least one of the first portion and the second portion is thicker than the flexing region.

[0007] In one embodiment, each of the first portion and the second portion is thicker than the flexure zone. In one embodiment, the flexure zone comprises one or more spiral arms, each of the one or more spiral arms interconnecting the first portion and the second portion.

[0008] In one embodiment, the plate includes a first surface and a second surface opposite the first surface; and the first surface is recessed relative to the at least one of the first portion and the second portion at the flexure zone.

[0009] Preferably, the second surface has no recesses.

[0010] Preferably, said second surface is recessed relative to said at least one of said first portion and said second portion at said flexure zone.

[0011] In one embodiment, a stack of multiple linear flexible bearings is provided, the multiple linear flexible bearings being connected together and comprising the first linear flexible bearing and one or more additional linear flexible bearings; wherein, when no bending force is applied to the stack, the distance between the flexure zone of the first linear flexible bearing and an adjacent linear flexible bearing in the stack is greater than the distance between at least one of the first portion and the second portion of the first linear flexible bearing and the adjacent linear flexible bearing.

[0012] In one embodiment, a stack of multiple linear flexible bearings is provided, the multiple linear flexible bearings being connected together and comprising the first linear flexible bearing and one or more additional linear flexible bearings; wherein each of the linear flexible bearings comprises a first portion, a second portion, and a flexure zone between the first portion and the second portion; and wherein, for at least two adjacent linear flexible bearings in the stack, a distance between the flexure zones is greater than at least one of a distance between the first portions and a distance between the second portions.

[0013] Preferably, for at least two adjacent linear flexible bearings in the stack, first portions of the at least two adjacent linear flexible bearings are in physical contact with each other, and / or second portions of the at least two adjacent linear flexible bearings are in physical contact with each other.

[0014] Preferably, the system further comprises: a linear motor; a piston arranged to move within the cylinder; and wherein the second part is rigidly connected to a stationary part of the linear motor and the first part is rigidly connected to the piston.

[0015] Preferably, the piston is part of a refrigerator.

[0016] A system is provided, including a linear flexible bearing assembly that extends generally along a plane when no bending force is applied to the linear flexible bearing assembly. The linear flexible bearing assembly includes: a first portion; a second portion that surrounds the first portion and is movable relative to the first portion when a bending force is applied transverse to the plane to cause the linear flexible bearing assembly to flex; and a flexure zone that includes a plurality of membranes, each membrane extending generally along the plane between the first portion and the second portion, and each membrane flexing when a bending force is applied to the assembly. At least one membrane is made of a continuous medium that continues into at least one of the first portion and the second portion and continues transversely to the membrane within at least one of the first portion and the second portion to protrude out of the plane of the membrane.

[0017] In one embodiment, the continuous medium continues into each of the first portion and the second portion and continues laterally to the membrane within each of the first portion and the second portion to protrude out of the plane of the membrane.

[0018] In one embodiment, each membrane is made of a continuous medium that continues into at least one of the first and second portions and that continues laterally to the membrane within at least one of the first and second portions to protrude out of the plane of the membrane.

[0019] In one embodiment, the continuous medium is thicker than the membrane at at least one of the first portion and the second portion.

[0020] A method is provided, comprising: obtaining a plate having a uniform thickness; and processing the plate to form a linear flexible bearing, wherein the processing comprises forming a flexure region in the plate, wherein forming the flexure region comprises forming one or more cavities to thin the plate at the location of the flexure region, the flexure region being thinner than the maximum thickness of the linear flexible bearing.

[0021] The scope of the present invention is defined by the claims, which are incorporated into this section by reference. A more complete understanding of the embodiments of the present invention and the realization of additional advantages of the present invention will be given to those skilled in the art by considering the following detailed description of one or more embodiments. Reference will be made to the accompanying drawings, which will first be briefly described. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1A-Figure 1C Included are perspective and cross-sectional views of flexible bearings and stacks of flexible bearings according to some embodiments of the present disclosure.

[0023] Figure 2 is a cross-sectional view of a flexible bearing according to some embodiments of the present disclosure.

[0024] Figure 3 and Figure 4 is a cross-sectional view of a piston assembly with a flexible bearing.

[0025] Figure 5 is a flow chart of a flexible bearing manufacturing process according to some embodiments of the present disclosure.

[0026] Figure 6 and Figure 7 is a cross-sectional view of a flexible bearing according to some embodiments of the present disclosure.

[0027] Figure 8 is a schematic diagram of a stack of flexible bearings according to some embodiments of the present disclosure.

[0028] Fig. 9 is a cross-sectional view of a chiller compressor assembly having a flexible bearing stack according to some embodiments of the present disclosure.

[0029] Embodiments of the present invention and their advantages are best understood by referring to the following detailed description.It should be understood that like reference numerals are used to identify like elements illustrated in one or more of the accompanying drawings. DETAILED DESCRIPTION

[0030] The embodiments described in this section illustrate but do not limit the present invention. The present invention is defined by the appended claims.

[0031] Linear flexible bearings can be formed as thin metal disks of sub-millimeter thickness (e.g., 0.7 mm) and can be used to provide a seal between a piston and a piston housing. The piston is attached to the center of the disk, and the housing is attached to the periphery (edge) of the disk. When the piston moves relative to the housing, the center of the disk is displaced axially relative to the edge, but the disk has a high radial stiffness (which may be hundreds or thousands of times higher than the axial stiffness), and the high radial stiffness limits the lateral movement of the piston to prevent the piston from contacting the housing. A precise narrow seal is maintained between the piston and the housing. Therefore, flexible bearings are superior to sliding bearings in terms of performance and device life.

[0032] In order to provide low stiffness in the axial direction, the flexible bearing includes a cutout between the central portion and the edge to form a flexure arm extending between the central portion and the edge.

[0033] If it is necessary to support lateral forces (i.e., forces that push the piston against the housing), the flexible bearings can be implemented in a stack to increase radial stiffness. The lateral forces can be generated by gravity, magnetic actuation, or other phenomena. Because the stack can allow for significant axial movement, the flexible bearings need to be spaced apart from each other within the stack to prevent their arms from contacting each other. Traditionally, this spacing is achieved by spacers inserted between the individual flexures at the center and the edges. See, for example, U.S. Patent No. 6,813,225, issued to Widdowson et al. on November 2, 2004, which is incorporated herein by reference.

[0034] The inventors have observed that as the number of spacers and flexures in a stack grows, alignment can become a problem. Some embodiments of the present disclosure help improve alignment in a stack by integrating a flexure with at least one spacer to form a single, integral part, thereby reducing the sum of alignment tolerances. The flexure is thicker at the center and edges and thinner between the center and the edges. Using such a flexure reduces the number of parts, thereby helping to improve the cost and assembly time of the flexure and the system using the flexure.

[0035] An exemplary flexure 110 is provided in Figure 1A-Figure 1C and exemplified in 2. Figure 1A-Figure 1C A perspective view of a single flexure 110 is shown at the top; and two vertical cross sections labeled II and II-II are shown at the bottom. The vertical cross sections illustrate the Figure 1A-Figure 1C The top of the diagram shows a stack of three flexures 110 of the same type. The II and II-II sections are taken at diametrically opposite sides of the annular flexure 110. The II and II-II sections are taken at a ratio of Figure 1A-Figure 1C The perspective view from the top is shown on a larger scale. For the sake of simplicity, the flexible cutouts 114 are not shown in sections II and II-II. Figure 2 A cross section of a single flexure 110 is shown.

[0036] The flexure 110 is a thin metal plate. The inner portion 110A of the flexure may be rigidly attached to the piston 210 ( Figure 3 , Figure 4 ), and more specifically to the piston extension (piston rod) 210E. The outer portion 110B of the flexure may be rigidly attached to the piston housing 214, and more specifically to the housing extension 214E. Figure 1A-Figure 1C and Figure 2 , the flexplate is shaped like a disk, and the inner portion 110A and the outer portion 110B are annular, but other shapes are possible, such as a rectangular shape for attachment to a rectangular (parallelepiped) piston 210.

[0037] The flexible member 110 includes a cutout 114 extending from the inner portion 110A to the outer portion 110B to form a flexible arm 118 between the cutouts. The flexible member 110 can be axially (eg, perpendicular to) a plane of the flexible member 110. Figure 3 and Figure 4 The flexure 110 has very high stiffness in the radial direction (along the plane of the flexure) to support lateral forces. The radial stiffness can be hundreds or thousands of times greater than the axial stiffness.

[0038] Figure 3 The piston position is shown so that the inner portion 110A is above the outer portion 110B; Figure 4 The piston position is shown so that the inner portion 110A is below the outer portion 110B. The piston 210 reciprocates in the A direction between two positions.

[0039] The flexure 110 includes mounting holes 120 at the outer portion 110B for attachment to the piston housing or other parts. The flexure may also include mounting holes in the inner portion 110A for attachment to the piston or other parts. There may be no mounting holes, as other types of attachment (e.g., clamps, solder, welding, etc.) are also possible.

[0040] As described above, the flexible bearings can be implemented in a stacked manner to increase radial stiffness. When implemented in a stacked manner, their flexible arms 118 should not touch each other. Rather than using separate spacers, the flexible members 110 can be made thicker where spacers might otherwise be desired. For example, the inner and outer portions 110A, 110B can be thicker than the flexure areas of the flexible arms 118. In this embodiment, the bottom side of each flexible member 110 is planar (e.g., Figure 1A-Figure 1C 110A and / or the outer portion 110B. In other embodiments, the thin portion 410 does not cover the entire area of ​​the flexible arm 118. The thin portion 410 may or may not extend into the inner portion 110A and / or the outer portion 110B beyond the cutout 114.

[0041] Adjacent flexures 110 are in physical contact with each other at the thick portions 420 rather than at the thin flexure regions (regions of the flexure arms 118). In some embodiments, the thick portions 420 of adjacent flexures are attached to each other by solder or other adhesive, and the thick portions 420 are separated from each other by an adhesive layer therebetween, but the axial gap (adhesive thickness) between adjacent thick portions 420 is smaller than the axial gap 330 ( Figure 1A-Figure 1C ).

[0042] The flexure dimensions may be selected to prevent adjacent flexure zones from contacting each other during axial displacement of the inner portion 110A relative to the outer portion 110B. In an exemplary embodiment, the thin portion 410 is annular, concentric with the inner portion 110A and the outer portion 110B, and includes only flexure zones, i.e., does not extend into the inner portion 110A and the outer portion 110B.

[0043] In some embodiments, each flexure 110 is an integral, one-piece structure made of metal (eg, spring steel). Figure 5 The manufacturing process is illustrated. The manufacturing process begins at step 510 using a plate of uniform thickness. Then, cavities (such as Figure 5 502 in the figure) to produce the thin portion 410. Then the cut 114 is formed (as shown in FIG. Figure 5 In some embodiments, the cutout 114 is formed only in the thin portion 410. In other embodiments, the cutout 114 extends into the thick portion 420. The cutout 114 may also be formed before the cavity, i.e., step 530 may be performed before step 520. Other manufacturing processes may also be used.

[0044] Thus, in some embodiments, the entire flexure is made of the same continuous material, or is made of multiple layers of possibly different materials that merge together to form a continuous medium for flexible operation. In some embodiments, all layers are metal. In some embodiments, the flexure is a crystalline material, such as a metal, which may be a single crystal. The present invention is not limited to a specific material or manufacturing process.

[0045] exist Figure 6 In the embodiment, the thick portion 420 is provided at the inner portion 110A instead of at the outer portion 110B. When stacking flexible bearings, spacers may be used at the outer portion. In other embodiments, the thick portion is provided at the outer portion 110B instead of at the inner portion 110A.

[0046] like Figure 7 For example, the thick portion 420 may protrude upward and downward relative to the thin portion (membrane) 410. Such a flexure 110 may be stacked with a prior art flexure of uniform thickness without a spacer between the prior art flexure and the flexure 110. Such a prior art flexure may be placed above and / or below the flexure 110.

[0047] More generally, flexure 110 may be stacked with other flexures, which may include prior art flexures, with or without spacers. For example, prior art flexures may be stacked on top of Figure 1A-Figure 1C and Figure 2 On the top of the flexible member 110, if the gap 330 ( Figure 1A-Figure 1C ) is sufficient to prevent contact between the flexure areas and the flexure areas of the prior art flexures, then there may be no spacer. Individual spacers may be provided between pairs of flexures, for example, where the axial gap 330 is missing or insufficient to prevent the flexures from contacting each other.

[0048] Some embodiments include tangential and / or other flexible geometries, such as disclosed in U.S. Pat. No. 5,492,313 issued to Pan et al. on February 20, 1996; U.S. Pat. No. 6,813,225 issued to Widdowson et al. on November 2, 2004; and U.S. Patent Publication No. 2015 / 0041619A1 published on February 12, 2015 (utility inventor: Ellis et al.), all of which are incorporated herein by reference. Such flexible geometries and other geometries may be modified as desired to include thicker portion 420 ( Figures 1A to 7 ), thereby providing flexing space for the flexing area.

[0049] Any number of flexible bearings can be stacked in many possible ways. Figure 8is a schematic cross-sectional view of an exemplary stack 710 of four flexure bearings. The top flexure bearing 714 is a conventional flexure of uniform thickness, and the remaining three flexures 110 are similar to Figure 1A-Figure 1C and Figure 2 The flexure 110 includes thick portions 420 at the inner portion 110A and the outer portion 110B. The inner rings of the respective flexures are connected to form an inner ring 710A which may be a stacking ring. The outer rings are connected to form an outer ring 710B which may be a stacking ring. The inner ring 710A which may be a stacking ring and the outer ring 710B which may be a stacking ring include the thick portions 420 of the bottom three flexures 110.

[0050] Each flexure 110 has a flexible membrane that can be formed as a continuous medium that is combined with and extends into one or both of an inner ring 710A that can be a stacking ring and an outer ring 710B that can be a stacking ring. Inside each inner ring 710A that can be a stacking ring and an outer ring 710B that can be a stacking ring, the continuous medium can extend upward and / or downward transversely to the membrane plane. This extension protrudes upward and / or downward beyond the membrane plane.

[0051] The top flexible bearing 714 may be omitted. Other variations are possible.

[0052] The flexible bearings disclosed herein have a wide range of applications, including in linear refrigerators and other devices. In refrigerators, flexible bearings can reduce or eliminate wear on the compressor and / or expander modules. Notably, the first refrigerator with flexible bearings was an Oxford-type Stirling refrigerator for space applications, where flexible bearings were used in the compressor and expander modules. Flexible bearings were later used in high performance military Stirling refrigerator designs, where flexible bearings were used almost exclusively in the compressor module.

[0053] Fig. 9 An example of a refrigerator compressor using a flexible member according to some embodiments of the present disclosure is shown in FIG. Fig. 9 Flexible bearing stacks 710 are provided at the top and bottom ends of the view of FIG. 2 (but the compressor can be operated in any spatial orientation). Each flexible bearing stack 710 can be any suitable stack described above to connect the moving part of the compressor to the stationary part of the compressor. The moving part includes a piston 210 and a moving linear motor element 715 of a motor that drives the piston. The moving linear motor element 715 is rigidly connected to the piston 210 to move together. The stationary part includes a compressor cylinder 719 in which the piston reciprocates, and includes a stationary linear motor element 725.

[0054] The flexible bearing stack 710 can be used with Figure 8 Each stack has an outer ring 710B (which may be a stacking ring) rigidly attached to the stationary portion of the compressor. Fig. 9 The inner ring 710A of the stacked rings may be rigidly attached to the moving part of the compressor (not marked in FIG. 1 ). Each flexure laterally surrounds the piston 210.

[0055] The present invention is not limited to the above-described embodiments. In particular, the present invention is not limited to specific dimensions, materials, geometric structures or other details. The use of the flexible member is not limited to pistons. Although the thickness of the flexible member may have only two values ​​at the thin portion 410 and the thick portion 420, the thickness may vary at more than two values, for example, different parts of the thin portion 410 or the thick portion 420 may differ in thickness. Further, the flexible member may or may not be circular; for example, some flexible member embodiments may be designed for non-circular pistons, such as for rectangular (parallelepiped-shaped) pistons. Other embodiments and modifications are within the scope of the present invention as defined by the appended claims.

Claims

1. A system comprising a first linear flexible bearing, characterized in that, The first linear flexure bearing comprises an integral one-piece plate; wherein the plate comprises a first portion, a second portion surrounding the first portion, and a flexure zone between the first portion and the second portion; and wherein at least one of the first portion and the second portion is thicker than the flexure zone; and The first portion is axially movable relative to the second portion, and the first portion and the second portion are rigidly attached to the respective first and second parts to maintain a predetermined seal between the first and second parts at the position of a linear flexible bearing when the first portion is axially movable relative to the second portion, and the linear flexible bearing has a radial stiffness higher than an axial stiffness.

2. The system according to claim 1, characterized in that Each of the first portion and the second portion is thicker than the flexure zone.

3. The system according to claim 1 or 2, characterized in that: The first portion is shaped like a ring or a rectangle; and The second portion is shaped like a ring or a rectangle.

4. The system according to claim 1, characterized in that The flexure zone includes one or more spiral arms, each of the one or more spiral arms interconnecting the first portion and the second portion.

5. The system according to claim 1, characterized in that: The plate includes a first surface and a second surface opposite the first surface; and The first surface is recessed relative to at least one of the first portion and the second portion at the flexure zone.

6. The system according to claim 5, characterized in that The second surface has no recessed portion.

7. The system according to claim 5, characterized in that The second surface is recessed relative to at least one of the first portion and the second portion at the flexure zone.

8. The system according to claim 1, characterized in that The system includes: a stack of a plurality of linear flexible bearings connected together and comprising the first linear flexible bearing and one or more additional linear flexible bearings; Wherein, when no bending force is applied to the stack, a distance between the flexure region of the first linear flexible bearing and an adjacent linear flexible bearing in the stack is greater than a distance between at least one of the first portion and the second portion of the first linear flexible bearing and the adjacent linear flexible bearing.

9. The system according to claim 1, characterized in that The system includes: a stack of a plurality of linear flexible bearings, the plurality of linear flexible bearings comprising the first linear flexible bearing and one or more additional linear flexible bearings; wherein each of the linear flexible bearings comprises a first portion, a second portion, and a flexure zone between the first portion and the second portion, each of the first portion and the second portion being thicker than the flexure zone; and Wherein, for every two adjacent linear flexible bearings in the stack, first portions of the two adjacent linear flexible bearings are in physical contact with each other, and second portions of the two adjacent linear flexible bearings are in physical contact with each other.

10. The system according to claim 1, characterized in that The system includes: a stack of a plurality of linear flexible bearings connected together and comprising the first linear flexible bearing and one or more additional linear flexible bearings; wherein each of the linear flexible bearings comprises a first portion, a second portion, and a flexure region between the first portion and the second portion; and Wherein, for at least two adjacent linear flexible bearings in the stack, a distance between the flexure zones is greater than at least one of a distance between the first portions and a distance between the second portions.

11. The system according to claim 10, characterized in that For at least two adjacent linear flexible bearings in the stack, first portions of the at least two adjacent linear flexible bearings are in physical contact with each other, and / or second portions of the at least two adjacent linear flexible bearings are in physical contact with each other.

12. The system according to claim 10, characterized in that The system also includes: Linear motors; a piston arranged to move within the cylinder; and wherein the second portion is rigidly connected to a second part comprising a stationary part of the linear motor, and the first portion is rigidly connected to a first part comprising the piston.

13. The system according to claim 1, characterized in that The system includes: a stack of a plurality of linear flexible bearings connected together and comprising the first linear flexible bearing and one or more additional linear flexible bearings, each linear flexible bearing in the stack physically contacting each adjacent linear flexible bearing in the stack; in: each of the one or more additional linear flexible bearings includes a first portion, a second portion, and a flexure zone between the first portion and the second portion; For at least two adjacent linear flexure bearings in the stack, a distance between the flexure zones is greater than at least one of a distance between the first portions and a distance between the second portions; The plate includes a first surface and a second surface opposite the first surface; the first surface being recessed relative to at least one of the first portion and the second portion at the flexure region; The second surface has no recesses; Wherein, the system further comprises: Linear motors; a piston arranged to move within the cylinder; and wherein the second portion is rigidly connected to a second part comprising a stationary part of the linear motor, and the first portion is rigidly connected to a first part comprising the piston.

14. The system according to claim 13, characterized in that The piston is part of a refrigerator.

15. The system according to claim 1, characterized in that The plate extends generally along a plane when no bending force is applied to the linear flexible bearing, the first portion being movable relative to the second portion to cause the linear flexible bearing to flex when a bending force is applied transverse to the plane; the flexure zone comprising a plurality of membranes, each membrane extending generally along the plane between the first portion and the second portion, and each membrane flexing when the bending force is applied to the assembly; and wherein at least one membrane is made of a continuous medium that continues into at least one of the first portion and the second portion and continues laterally to the membrane within the at least one of the first portion and the second portion to protrude out of the plane of the membrane.

16. The system according to claim 15, characterized in that The continuous medium continues into each of the first portion and the second portion and continues laterally to the membrane within each of the first portion and the second portion to protrude out of the plane of the membrane.

17. The system according to claim 15, characterized in that Each membrane is made of a continuous medium that continues into at least one of the first portion and the second portion and continues laterally to the membrane within at least one of the first portion and the second portion to protrude out of the plane of the membrane.

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