Flexible expander power system

Abstract

This disclosure relates to the field of engine technology, and in particular to a flexible expander power system, comprising: a flexible piston and a connecting rod motion mechanism. The flexible piston includes a piston chamber and a piston connecting rod. The piston chamber is axially expandable and contractable. The piston connecting rod is disposed at the top of the piston chamber, and the piston connecting rod can be driven to move during the expansion and contraction of the piston chamber. The connecting rod motion mechanism connects to the piston connecting rod and can restrict the axial movement of the piston connecting rod along the piston chamber. This disclosure can achieve approximately or precisely linear motion of the entire piston connecting rod along the axial direction, ensuring that the axis of the piston connecting rod does not undergo significant offset or rotation, thereby improving energy efficiency.

Description

Technical Field

[0001] This disclosure relates to the field of engine technology, and in particular to a flexible expander power system based on a rolling pair linear motion linkage mechanism. Background Technology

[0002] Energy conservation and emission reduction have always been key concerns for various industries, including energy, chemical, electrical, and construction, in the new era. The development and utilization of low-temperature heat sources has been a focus, but significant challenges remain. Low-temperature heat sources are widespread and abundant, including geothermal energy, industrial waste heat, and solar energy. However, according to the second law of thermodynamics and the Carnot cycle, due to the extremely low temperatures, the value of converting these heat sources into kinetic or electrical energy is very low, and the conversion efficiency is also very low. This results in poor economic efficiency for existing thermodynamic conversion devices applied to low-temperature heat source applications, sometimes even with self-loss exceeding the energy converted from the low-temperature heat source. Therefore, the current utilization of low-temperature heat sources is largely limited to heat utilization forms, such as developing geothermal hot springs, geothermal heat pumps, and industrial waste heat heating. However, this heat cannot be utilized in summer or in areas where heating is not required. Therefore, the development of cheaper and more efficient low-temperature heat source expanders is urgently needed.

[0003] For piston-type expanders and compressors, mechanical losses mainly occur in the piston assembly. To address this, existing technologies utilize variable-volume pistons and flexible pistons to reduce friction and leakage losses, thereby lowering mechanical losses and enabling the conversion and utilization of waste heat at temperatures below 150°C. However, the power output and transmission mechanisms of existing piston assemblies are not suitable for the new flexible piston structure. Because there is a large gap between the power output portion of the flexible piston and the cylinder, the cylinder only serves to support other components, and in some structures, there is no cylinder at all. Therefore, it is impossible to achieve circumferential positioning between the piston wall and the cylinder wall to output linear motion. Thus, the transmission mechanism of the existing piston engine needs to be improved to achieve circumferential positioning for linear piston motion while minimizing frictional resistance losses, adapting to the low thermal efficiency and low utilization value of the low-temperature heat source. Furthermore, to increase output power and convert linear motion into rotary motion compatible with conventional generators, piston expanders often need to be used in parallel. Currently common parallel mechanisms, such as radial engine structures and crankshaft connecting rod mechanisms, inevitably introduce lateral forces on piston movement. Therefore, the output mechanism of a flexible piston also needs to resist a certain degree of lateral force. Summary of the Invention

[0004] This disclosure is made in view of the above-mentioned problems. This disclosure provides a flexible expander power system.

[0005] According to one aspect of this disclosure, a flexible expander power system is provided, comprising:

[0006] A flexible piston includes a piston chamber and a piston connecting rod. The piston chamber is capable of axial extension and retraction, and the piston connecting rod is disposed at the top of the piston chamber. During the extension and retraction of the piston chamber, the piston connecting rod can be driven to move. A linkage mechanism is provided, which connects to the piston rod and restricts the axial movement of the piston rod along the piston chamber.

[0007] Furthermore, according to one aspect of the flexible expander power system of this disclosure, the linkage mechanism is a Watt's linkage linear mechanism, comprising: The first watt link, wherein the middle movable link of the first watt link is hinged to the piston link; The second Watt's linkage has a central movable link that is hinged to the piston linkage, and the second Watt's linkage is closer to the piston chamber than the first Watt's linkage.

[0008] Furthermore, according to one aspect of the flexible expander power system of this disclosure, the flexible piston comprises: A flexible membrane having an accordion-like folded structure surrounds the piston cavity circumferentially, the piston cavity being able to expand when inflated and contract when deflated.

[0009] Furthermore, according to one aspect of the flexible expander power system of this disclosure, the flexible piston further includes: A piston bottom cover is disposed at the bottom of the piston chamber and is fixedly connected to the bottom of the piston chamber. The piston bottom cover remains fixed during the extension and retraction of the piston chamber. A piston top cover is disposed on the top of the piston chamber and is fixedly connected to the top of the piston chamber. During the extension and retraction of the piston chamber, the piston top cover moves accordingly. The piston connecting rod is disposed on the piston top cover.

[0010] Furthermore, according to one aspect of the flexible expander power system of this disclosure, the flexible piston further includes: An intake and exhaust valve is disposed on the piston bottom cover and communicates with the piston chamber. The intake and exhaust valve includes multiple intake ports and exhaust ports, and the intake ports and exhaust ports are set at a preset angle.

[0011] Furthermore, according to one aspect of the flexible expander power system of this disclosure, the flexible piston further includes: A piston bottom flange is disposed on the piston bottom cover, which seals and fixes the bottom end of the piston chamber to the piston bottom cover. A piston top flange is disposed on the piston top cover, which seals and fixes the top end of the piston chamber to the piston top cover.

[0012] Furthermore, the flexible expander power system according to one aspect of this disclosure also includes: A connecting rod mounting base plate is provided, and the connecting rod motion mechanism is mounted on the connecting rod mounting base plate and deforms on the connecting rod mounting base plate.

[0013] Furthermore, the flexible expander power system according to one aspect of this disclosure also includes: The first expander mounting bracket is located on the left side of the piston chamber and is connected and fixed to the connecting rod mounting base plate; The second expander mounting bracket is located on the right side of the piston chamber and is connected and fixed to the connecting rod mounting base plate; The piston bottom cover is connected and fixed to the first expander mounting bracket and the second expander mounting bracket.

[0014] Furthermore, according to one aspect of the flexible expander power system of this disclosure, the piston chamber and the piston top cover are movable between the first expander mounting bracket and the second expander mounting bracket.

[0015] Furthermore, according to one aspect of the flexible expander power system of this disclosure, the linkage mechanism is any one of: a three-bar linear mechanism, a Chebyshev linear mechanism, a Robert linear mechanism, a Posellier linear mechanism, a Kemp linear mechanism, a Hart first linear mechanism, and a Hart second linear mechanism.

[0016] According to the flexible expander power system of this disclosure, by setting a flexible piston and a connecting rod motion mechanism, the flexible piston does not have the function of limiting the direction of movement, while the connecting rod motion mechanism can limit the movement trajectory of the flexible piston and can withstand loads in all directions. In order to achieve the entire piston and connecting rod to move in a straight line along the axial direction approximately or precisely, without the piston and connecting rod axis producing a large offset or rotation process, only a rotating pair is used, without any sliding pair, gear pair, etc. Therefore, there is only rotational friction and no sliding friction. The frictional force of rotational friction can be effectively reduced by mature bearings, which avoids the large wear and consumption that may be caused by the lateral force during sliding friction, and also avoids the use of linear bearings, thus enabling high-speed medium-load movement.

[0017] It should be understood that both the foregoing general description and the following detailed description are exemplary and intended to provide further illustration of the claimed technology. Attached Figure Description

[0018] The above and other objects, features, and advantages of this disclosure will become more apparent from the more detailed description of the embodiments thereof in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of this disclosure and form part of the specification. They are used together with the embodiments of this disclosure to explain the disclosure and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same components or steps.

[0019] Figure 1 This is a schematic diagram of the compression state of the flexible expander power system according to an embodiment of the present disclosure; Figure 2 This is a schematic diagram of the expansion state of the flexible expander power system according to an embodiment of the present disclosure; Figure 3 A schematic diagram of a single-link three-bar linear mechanism according to an embodiment of the present disclosure; Figure 4 A schematic diagram of a double Chebyshev linkage linear mechanism according to an embodiment of the present disclosure; Figure 5 A schematic diagram of a double-group Robert linkage linear mechanism according to an embodiment of the present disclosure; Figure 6 A schematic diagram of a same-side double-group Posellier linkage linear mechanism according to an embodiment of the present disclosure; Figure 7 This is a schematic diagram of a non-circular double-group Posellier linkage linear mechanism according to an embodiment of the present disclosure.

[0020] Explanation of reference numerals in the attached figures: Piston bottom cover 1, intake and exhaust valves 2, intake port 3, piston bottom flange 4, piston chamber 5, piston top cover 6, piston top flange 7, piston connecting rod 8, connecting rod mounting base plate 9, first Watt's connecting rod 10, second Watt's connecting rod 11, first expander mounting bracket 12, second expander mounting bracket 13, exhaust port 14, three-link 20, first Chebyshev connecting rod 30, second Chebyshev connecting rod 31, first Robert connecting rod 40, second Robert connecting rod 41, first Posellier connecting rod 50, second Posellier connecting rod 51. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this disclosure more apparent, exemplary embodiments according to this disclosure will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this disclosure, and not all embodiments of this disclosure. It should be understood that this disclosure is not limited to the exemplary embodiments described herein.

[0022] This disclosure provides a flexible expander power system that enables the entire piston connecting rod to move in a straight line approximately or precisely along the axial direction, ensuring that the piston connecting rod axis does not undergo significant offset or rotation, thereby improving energy efficiency.

[0023] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0024] like Figure 1 , Figure 2 As shown, this disclosure provides a flexible expander power system, including: a flexible piston and a connecting rod motion mechanism; The flexible piston includes a piston chamber 5 and a piston connecting rod 8. The piston chamber 5 can extend and retract axially. The piston connecting rod 8 is located at the top of the piston chamber 5. During the extension and retraction of the piston chamber 5, the piston connecting rod 8 can be driven to move. The piston chamber 5 can do work during the extension and retraction process and drive certain mechanisms to operate externally through the piston connecting rod 8. The linkage mechanism connects to the piston connecting rod 8 and is used to limit the movement trajectory of the piston connecting rod 8. It can limit the axial movement of the piston connecting rod 8 along the piston chamber 5, and the entire piston connecting rod moves in a straight line approximately or precisely along the axial direction, ensuring that the axis of the piston connecting rod does not produce large offsets or rotations, so as to meet the driving needs.

[0025] In some possible implementations, such as Figure 1 , Figure 2 As shown, the linkage mechanism is a Watt's linkage linear mechanism, including: a first Watt's linkage 10 and a second Watt's linkage 11; the Watt's linkage is a four-bar linkage linear mechanism, including the connecting rods on the left and right sides, the movable connecting rod in the middle, and the fixed frame (served by the connecting rod mounting base plate 9).

[0026] The two connecting rods of the first Watt connecting rod 10 are located on the left and right sides of the piston connecting rod 8, respectively, with a certain height difference between them. The middle movable connecting rod is hinged to the piston connecting rod 8 and can rotate in the hinged position. The two connecting rods of the second Watt's connecting rod 11 are located on the left and right sides of the piston connecting rod 8, with a certain height difference between them. The middle movable connecting rod is hinged to the piston connecting rod 8 and can rotate in the hinged position. The second Watt's connecting rod 11 is closer to the piston chamber 5 than the first Watt's connecting rod 10.

[0027] A single Watt's linkage can only limit the motion trajectory of a single point to an approximate straight line, and this point itself also has rotational motion. To achieve the linear motion of the piston connecting rod 8, two Watt's linkages of the same size are required, which are arranged vertically along the axis of the linear motion of the piston connecting rod 8. By using two Watt's linkages, the piston connecting rod 8 can be limited to move along an approximate straight line, and the resulting axial offset and rotation are very small.

[0028] In some possible implementations, such as Figure 1 , Figure 2As shown, the flexible piston includes a flexible membrane with an accordion-like folded structure. An internal skeleton can be installed, forming a piston chamber 5 around the periphery. The piston chamber 5 expands when inflated and contracts when deflated. The flexible membrane is a flexible component and does not itself have the function of positioning or restricting the displacement of other components; it moves along with the piston top cover 6 connected to it.

[0029] In some possible implementations, such as Figure 1 , Figure 2 As shown, the flexible piston also includes: piston bottom cover 1 and piston top cover 6; The piston bottom cover 1 is usually designed to be circular. The piston bottom cover 1 is located at the bottom of the piston cavity 5 and is fixedly connected to the bottom of the piston cavity 5. During the extension and retraction of the piston cavity 5, the piston bottom cover 1 remains fixed to prevent the two ends of the piston cavity 5 from moving. The piston top cover 6 is usually designed to be circular. The piston top cover 6 is located on the top of the piston cavity 5 and is fixedly connected to the top of the piston cavity 5. During the extension and retraction of the piston cavity 5, the piston top cover 6 moves accordingly. The piston connecting rod 8 is located on the piston top cover 6. The piston top cover 6 drives the piston connecting rod 8 to move, and the two have the same motion trajectory.

[0030] In some possible implementations, such as Figure 1 , Figure 2 As shown, the flexible piston also includes an intake / exhaust valve 2, which is located on the piston bottom cover 1 and connects to the piston chamber 5. The intake / exhaust valve 2 includes multiple intake ports 3 and exhaust ports 14, which are spaced at a preset angle. Gas is input through the intake ports 3, causing the piston chamber 5 to expand. When the piston chamber 5 contracts, gas is discharged through the exhaust ports 14. For example, there are four intake / exhaust ports in total. Two intake ports 3 are arranged symmetrically at 180°, and two exhaust ports 14 are also arranged symmetrically at 180°, with the two pairs of intake / exhaust ports spaced 90° apart.

[0031] In some possible implementations, such as Figure 1 , Figure 2 As shown, the flexible piston also includes: piston bottom flange 4 and piston top flange 7; The piston bottom flange 4 is usually designed to be circular. The piston bottom flange 4 is set on the piston bottom cover 1 and seals and fixes the bottom end of the piston chamber 5 to the piston bottom cover 1. The piston bottom flange 4 can be fixed to the piston bottom cover 1 with screws to ensure that it does not leak air and does not separate. The piston top flange 7 is usually designed to be circular. The piston top flange 7 is set on the piston top cover 6 and seals and fixes the top of the piston cavity 5 to the piston top cover 6. The piston top flange 7 can be fixed to the piston bottom cover 1 with screws to ensure that it does not leak air and does not separate.

[0032] In some possible implementations, such as Figure 1 , Figure 2 As shown, the flexible expander power system also includes: a connecting rod mounting base plate 9, on which the connecting rod motion mechanism is mounted and deforms. The connecting rod mounting base plate 9 serves as the fixed frame in the Watt's connecting rod, and the connecting rods on the left and right sides are respectively hinged to the connecting rod mounting base plate 9, allowing them to rotate relative to each other at the hinged positions.

[0033] In some possible implementations, such as Figure 1 , Figure 2 As shown, the flexible expander power system also includes: a first expander mounting bracket 12 and a second expander mounting bracket 13; The first expander mounting bracket 12 is located on the left side of the piston chamber 5 and is connected and fixed to the connecting rod mounting base plate 9; The second expander mounting bracket 13 is located on the right side of the piston chamber 5 and is connected and fixed to the connecting rod mounting base plate 9; The piston bottom cover 1 is connected and fixed to the first expander mounting bracket 12 and the second expander mounting bracket 13, so as to remain fixed during the extension and retraction of the piston chamber 5.

[0034] In some possible implementations, such as Figure 1 , Figure 2 As shown, the piston chamber 5 and piston top cover 6 move between the first expander mounting bracket 12 and the second expander mounting bracket 13. The first expander mounting bracket 12 and the second expander mounting bracket 13 can protect the mechanism, especially to prevent other objects from colliding with the piston chamber 5.

[0035] In some possible implementations, the linkage mechanism may employ other types of linear mechanisms, such as: a three-bar linear mechanism, a Chebyshev linear mechanism, a Robert linear mechanism, a Posellier linear mechanism, a Kempe linear mechanism, a Hart first linear mechanism, or a Hart second linear mechanism. These linear mechanisms can achieve functions similar to the Watt linkage, enabling the entire piston rod 8 to move approximately or precisely along the axial direction, ensuring that the axis of the piston rod 8 does not undergo significant offset or rotation.

[0036] like Figure 3 The diagram shown is a schematic of a single-group three-bar linear mechanism according to an embodiment of the present disclosure. A specific three-bar linear mechanism can be used alone to achieve approximately or precisely linear motion of the entire piston rod 8 along the axial direction, without significant offset or rotation of the piston rod 8's axis. Figure 4 The diagram shown is a schematic representation of a double-set Chebyshev linkage linear mechanism according to an embodiment of this disclosure; as shown... Figure 5 The diagram shown is a schematic representation of a double-group Robert linkage linear mechanism according to an embodiment of this disclosure; as follows: Figure 6The diagram shown is a schematic representation of a double-set Posellier linkage linear mechanism on the same side according to an embodiment of this disclosure; as shown... Figure 7 The diagram shown is a schematic of a double-group Posellier linkage linear mechanism on opposite sides according to an embodiment of the present disclosure.

[0037] Approximate linear mechanisms such as the Chebyshev linkage and the Robert linkage require that the two sets of links be arranged on the same side of the motion axis, with both sets of links having the same dimensions and arranged vertically along the axis of linear motion. In contrast, precise linear mechanisms such as the Kempe linkage, the Hart first linear mechanism, the Hart second linear mechanism, and the Posellier linkage can arrange the two sets of links on the same or opposite sides of the motion axis, with both sets of links having the same dimensions and arranged vertically along the direction of motion.

[0038] The flexible expander power system according to an embodiment of the present disclosure has been described above with reference to the accompanying drawings, and has the following advantages: By setting up a flexible piston and connecting rod motion mechanism, the flexible piston does not have the function of limiting the direction of movement, while the connecting rod motion mechanism can limit the movement trajectory of the flexible piston and can withstand loads in all directions. In order to achieve approximately or precisely linear motion of the entire piston and connecting rod along the axial direction, without significant offset of the piston and connecting rod axis and during the rotation process, only a revolute joint is used, without any sliding joints, gears, etc. Therefore, there is only rotational friction and no sliding friction. The frictional force of rotational friction can be effectively reduced by mature bearings, which avoids the large wear and consumption that may be caused by lateral forces during sliding friction, and also avoids the use of linear bearings, enabling high-speed medium-load motion.

[0039] The basic principles of this disclosure have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this disclosure are merely examples and not limitations, and should not be considered as essential features of each embodiment of this disclosure. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the scope of this disclosure to the necessity of employing the aforementioned specific details for implementation.

[0040] The block diagrams of devices, apparatuses, devices, and systems disclosed herein are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0041] Additionally, as used herein, the "or" used in a list of items beginning with "at least one" indicates a separate list, such that a list of, for example, "at least one of A, B, or C" means A or B or C, or AB or AC or BC, or ABC (i.e., A and B and C). Furthermore, the word "exemplary" does not imply that the described example is preferred or better than other examples.

[0042] It should also be noted that in the systems and methods of this disclosure, the components or steps can be decomposed and / or recombined. These decompositions and / or recombinations should be considered as equivalent solutions to this disclosure.

[0043] Various changes, substitutions, and modifications can be made to the technology described herein without departing from the teachings defined by the appended claims. Furthermore, the scope of the claims of this disclosure is not limited to the specific aspects of the processes, machines, manufactures, events, means, methods, and actions described above. Currently existing or later-developed processes, machines, manufactures, events, means, methods, or actions that perform substantially the same function or achieve substantially the same result as the corresponding aspects described herein can be utilized. Therefore, the appended claims include such processes, machines, manufactures, events, means, methods, or actions within their scope.

[0044] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of this disclosure. Therefore, this disclosure is not intended to be limited to the aspects shown herein, but rather to be carried out within the widest scope consistent with the principles and novel features disclosed herein.

[0045] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this disclosure to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations therein.

Claims

1. A flexible expander power system, characterized in that, include: A flexible piston, comprising a piston chamber (5) and a piston connecting rod (8), wherein the piston chamber (5) is capable of axial extension and retraction, and the piston connecting rod (8) is disposed at the top of the piston chamber (5), and the piston connecting rod (8) can be driven to move during the extension and retraction of the piston chamber (5); A linkage mechanism is provided, which connects to the piston rod (8) and is capable of restricting the piston rod (8) from moving axially along the piston chamber (5).

2. The flexible expander power system according to claim 1, characterized in that, The linkage mechanism is a Watt's linkage linear mechanism, including: The first Watt link (10) has a central movable link that is hinged to the piston link (8); The second Watt link (11) has a central movable link that is hinged to the piston link (8), and the second Watt link (11) is closer to the piston chamber (5) than the first Watt link (10).

3. The flexible expander power system according to claim 1, characterized in that, The flexible piston includes: The flexible membrane has an accordion-style folded structure and surrounds the piston cavity (5) in the circumferential direction. The piston cavity (5) can expand when filled with air and contract when discharged.

4. The flexible expander power system according to claim 3, characterized in that, The flexible piston also includes: Piston bottom cover (1), the piston bottom cover (1) is disposed at the bottom of the piston cavity (5) and is fixedly connected to the bottom of the piston cavity (5). During the extension and retraction of the piston cavity (5), the piston bottom cover (1) remains fixed. Piston top cover (6) is located on the top of the piston chamber (5) and is fixedly connected to the top of the piston chamber (5). During the extension and retraction of the piston chamber (5), the piston top cover (6) moves accordingly. The piston connecting rod (8) is located on the piston top cover (6).

5. The flexible expander power system according to claim 4, characterized in that, The flexible piston also includes: An intake and exhaust valve (2) is provided on the piston bottom cover (1) and connected to the piston chamber (5). The intake and exhaust valve (2) includes multiple intake ports (3) and exhaust ports (14). The intake ports (3) and exhaust ports (14) are set at a preset angle.

6. The flexible expander power system according to claim 4, characterized in that, The flexible piston also includes: Piston bottom flange (4), the piston bottom flange (4) is disposed on the piston bottom cover (1), and the bottom end of the piston cavity (5) is sealed and fixedly connected to the piston bottom cover (1); The piston top flange (7) is disposed on the piston top cover (6) to seal and fix the top end of the piston cavity (5) to the piston top cover (6).

7. The flexible expander power system according to claim 4, characterized in that, Also includes: The connecting rod mounting base plate (9) is provided on the connecting rod mounting base plate (9) and deforms on the connecting rod mounting base plate (9).

8. The flexible expander power system according to claim 7, characterized in that, Also includes: The first expander mounting bracket (12) is located on the left side of the piston chamber (5) and is connected and fixed to the connecting rod mounting base plate (9); The second expander mounting bracket (13) is located on the right side of the piston chamber (5) and is connected and fixed to the connecting rod mounting base plate (9); The piston bottom cover (1) is connected and fixed to the first expander mounting bracket (12) and the second expander mounting bracket (13).

9. The flexible expander power system according to claim 8, characterized in that, The piston chamber (5) and the piston top cover (6) move between the first expander mounting bracket (12) and the second expander mounting bracket (13).

10. The flexible expander power system according to claim 1, characterized in that, The linkage mechanism is any one of the following: a three-bar linear mechanism, a Chebyshev linear mechanism, a Robert linear mechanism, a Posellier linear mechanism, a Kemp linear mechanism, a Hart first linear mechanism, or a Hart second linear mechanism.

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