A permanent magnet eddy current damping air-floating frictionless pneumatic actuator

Abstract

The present invention discloses a permanent magnet electric eddy current damping air-floating frictionless pneumatic actuator, comprising a cylinder, an air-floating piston located inside the cylinder, a piston rod extending into the air-floating piston at one end, a built-in permanent magnet located inside the air-floating piston, a cylinder front end cover and a cylinder rear end cover provided at both ends of the cylinder, and a buffer component provided opposite the air-floating piston; the air-floating piston is a cavity structure with one end open, and a plurality of throttle holes are evenly provided along the side wall to connect the cavity inside the air-floating piston and the gap between the air-floating piston and the inner wall of the cylinder; a plurality of axial air passages that are not connected to the throttle holes are provided in the side wall of the air-floating piston, and a first annular pressure relief groove and a second annular pressure relief groove are provided on the outer side walls of the two ends of the air-floating piston, respectively. The present invention has the characteristics of high integration by integrating the built-in permanent magnet into the air-floating piston, thereby avoiding the built-in permanent magnet occupying additional space in the cylinder, thereby avoiding the built-in permanent magnet affecting the effective stroke of the air-floating piston in the cylinder.

Description

Technical Field

[0001] The present invention relates to the technical field of pneumatic actuators, in particular to a permanent magnet eddy current damping air-floating frictionless pneumatic actuator. Background Art

[0002] Pneumatic systems use compressed air as a medium for energy and signal transmission. As one of the most common actuators in pneumatic systems, the cylinder boasts advantages such as simple structure and clean, pollution-free operation. Its smooth, continuous, and controllable motion makes it an excellent choice for fine grinding applications, such as those involving brittle materials like cast iron, glass, and ceramics.

[0003] Because traditional pneumatic cylinders exhibit uncertain, time-varying friction, their output force control accuracy is often low. In recent years, air-floating frictionless cylinders have been proposed. These cylinders utilize a high-pressure air film for lubrication and load-bearing, preventing direct contact between the friction pairs. Consequently, their output force is freed from the constraints of friction, enabling ultra-high-precision output force control. For example, Chinese Invention Patent Application No. 201711223571.1 discloses a universal double-acting air-floating frictionless cylinder. This utilizes an air bearing and an air-floating piston to eliminate contact between the piston rod and front end cap, and between the piston and the inner wall of the cylinder barrel, achieving frictionless motion. However, the extremely low air film damping in this type of cylinder can easily cause oscillation in the control system, compromising high-precision position servo control. Chinese Invention Patent Application No. 202211011690.1 discloses an air-floating cylinder with eddy current damping and a damping coefficient test device. However, this type of cylinder reduces the effective stroke of the cylinder by placing permanent magnets at the front or rear end of the air-floating piston, resulting in a low level of integration. Therefore, it is necessary to design a new type of cylinder with high internal integration and contactless damping. Summary of the Invention

[0004] In response to the problems of low control precision and low integration of existing cylinders, the present invention provides a permanent magnet eddy current damping air-floating frictionless pneumatic actuator. By integrating the built-in permanent magnet into the interior of the air-floating piston, it has the characteristics of high integration, avoiding the built-in permanent magnet occupying additional space in the cylinder, and thus avoiding the built-in permanent magnet affecting the effective stroke of the air-floating piston in the cylinder. In addition, the piston rod is configured as a detachable split structure in the present invention, which facilitates the installation of the built-in permanent magnet on the piston rod, and further facilitates the integration of the built-in permanent magnet into the interior of the air-floating piston. At the same time, the provision of the built-in permanent magnet can generate eddy current damping when the actuator is working to absorb the vibration energy generated during the movement, thereby reducing vibration and improving the motion control accuracy of the pneumatic actuator.

[0005] The technical solution adopted by the present invention is:

[0006] A permanent magnet eddy current damping air-floating frictionless pneumatic actuator comprises a cylinder, an air-floating piston located inside the cylinder, a piston rod with one end extending into the air-floating piston, a built-in permanent magnet located in the air-floating piston, a cylinder front end cover and a cylinder rear end cover provided at both ends of the cylinder, and a buffer component provided directly opposite the air-floating piston; each cylinder front end cover and cylinder rear end cover are provided with an air vent connecting the outside with the internal cavity of the cylinder;

[0007] The air-floating piston is a cavity structure with an open end, and a number of throttle holes connecting the internal cavity of the air-floating piston and the gap between the air-floating piston and the inner wall of the cylinder are evenly arranged along the side wall; a number of axial air passages that are not connected to the throttle holes are provided in the side wall of the air-floating piston, and a first annular pressure relief groove and a second annular pressure relief groove are respectively provided on the outer side walls of the two end portions of the air-floating piston, a small cavity is provided on the inner wall of the end face of the air-floating piston, a first exhaust hole connected to the axial air passage is provided at the bottom of the first annular pressure relief groove, and a second exhaust hole connected to the axial air passage and the small cavity is provided at the bottom of the second annular pressure relief groove;

[0008] The piston rod comprises a piston rod outer shaft body, a connecting piece and a piston rod rear end member which are detachably connected in sequence, and a piston rod inner shaft body which passes through the piston rod outer shaft body and the connecting piece in sequence and is detachably fixedly connected to the piston rod rear end member; an air outlet channel which extends axially to communicate with the small cavity is provided in the piston rod inner shaft body; an annular air inlet channel is formed between the piston rod inner shaft body and the piston rod outer shaft body, and an air supply hole which communicates with the annular air inlet channel and the internal cavity of the air-floating piston is provided in the connecting piece; a piston front end cover which is detachably fixedly connected to one end of the air-floating piston opening is fixed on the piston rod outer shaft body; the built-in permanent magnet comprises a permanent magnet A and a permanent magnet B which are respectively sleeved on the piston rod outer shaft body and the piston rod rear end member;

[0009] The buffer device includes a front cover buffer permanent magnet and a rear cover buffer permanent magnet respectively installed on the front cover and rear cover of the cylinder; the front cover buffer permanent magnet has the same magnetic pole as permanent magnet A, and the rear cover buffer permanent magnet has the same magnetic pole as permanent magnet B.

[0010] Furthermore, an air bearing is provided between the piston rod and the front end cover of the cylinder.

[0011] Furthermore, the throttle hole is provided on the throttle module, the throttle module is threadedly connected to the side wall of the air floating piston, and a plurality of blind holes not connected to the throttle hole are provided on the end face of the throttle module.

[0012] Furthermore, a front end buffer rubber ring and a rear end buffer rubber ring are respectively provided on the front end cover buffer permanent magnet and the rear end cover buffer permanent magnet.

[0013] Furthermore, the inner shaft body of the piston rod and the rear end component of the piston rod are threadedly connected; a piston rod rear end sealing ring is provided at the connection between the inner shaft body of the piston rod and the rear end component of the piston rod; the connecting piece and the outer shaft body of the piston rod and the rear end component of the piston rod are threadedly connected; the front end cover of the piston and the air floating piston are threadedly connected.

[0014] Furthermore, the front end cover of the piston is stepped and has an outer conical structure at the shoulder. A matching inner conical structure is provided at one end of the opening of the air-floating piston and at a position corresponding to the outer conical structure on the front end cover of the piston.

[0015] Furthermore, the inner shaft of the piston rod is arranged in a stepped shape at one end away from the air-floating piston and has an outer conical structure at the shoulder. A matching inner conical structure is provided on the outer shaft of the piston rod at a position corresponding to the outer conical structure on the inner shaft of the piston rod to achieve conical matching; a piston rod front end sealing ring is provided at the conical matching position between the outer shaft of the piston rod and the inner shaft of the piston rod.

[0016] Furthermore, the contact surface between the connector and the built-in permanent magnet is provided with an outer sealing groove, and the contact surface between the connector and the piston rod outer shaft body and the piston rod rear end component is provided with an inner sealing groove; sealing rings are provided on both the outer sealing groove and the inner sealing groove.

[0017] Furthermore, the connecting member is made of ferromagnetic material; the poles of the permanent magnet A and the permanent magnet B are opposite to each other.

[0018] Furthermore, the outer ring of the cylinder is equipped with a magnetic isolation sleeve; the material of the magnetic isolation sleeve is ferromagnetic material.

[0019] The beneficial effects of the present invention are:

[0020] The permanent magnet eddy current damping air-floating frictionless pneumatic actuator described in the present invention has the characteristics of high integration by integrating the built-in permanent magnet into the interior of the air-floating piston, thereby avoiding the built-in permanent magnet from occupying additional space in the cylinder, thereby avoiding the built-in permanent magnet from affecting the effective stroke of the air-floating piston in the cylinder. In addition, the piston rod is configured as a detachable split structure in the present invention, which facilitates the installation of the built-in permanent magnet on the piston rod, thereby facilitating the integration of the built-in permanent magnet into the interior of the air-floating piston. At the same time, the provision of the built-in permanent magnet enables the actuator to generate eddy current damping when working to absorb the vibration energy generated during the movement, thereby reducing vibration and improving the motion control accuracy of the pneumatic actuator.

[0021] The permanent magnet eddy current damping air-floating frictionless pneumatic actuator described in the present invention has a front cover buffer permanent magnet and a rear cover buffer permanent magnet installed on the front cover and rear cover of the cylinder, respectively. The interaction between the permanent magnets arranged at both ends and the permanent magnets inside the air-floating piston achieves buffering when the air-floating piston moves at both ends of the cylinder barrel, preventing the air-floating piston from rapidly impacting the front cover and rear cover of the cylinder, thereby avoiding damage caused by rapid impact. In addition, the present invention can also adjust the buffer distance by changing the material or structural parameters of the front cover buffer permanent magnet and the rear cover buffer permanent magnet, thereby adjusting the effective stroke of the pneumatic actuator.

[0022] The present invention forms a total air intake channel of an annular air intake channel → air supply hole → internal cavity of the air floating piston → throttle hole → gap between the air floating piston and the inner wall of the cylinder, and forms a total air outlet channel of the gap between the air floating piston and the inner wall of the cylinder → first annular pressure relief groove → first exhaust hole → axial air channel → second exhaust hole → small cavity → air outlet channel and gap between the air floating piston and the inner wall of the cylinder → second annular pressure relief groove → second exhaust hole → small cavity → air outlet channel. By forming a high-pressure air film in the gap between the air floating piston and the inner wall of the cylinder, direct contact between the air floating piston and the inner wall of the cylinder is avoided, and friction-free operation is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a structural schematic diagram of the permanent magnet eddy current damping air-floating frictionless pneumatic actuator of the present invention.

[0024] Figure 2 It is a partial schematic diagram of the air-floating piston of the present invention.

[0025] Figure 3 It is a three-dimensional schematic diagram of the throttling module of the present invention.

[0026] Figure 4 This is a schematic diagram of the connection between the air-floating piston, piston rod, and built-in permanent magnet of the present invention.

[0027] Figure 5 This is a partial schematic cross-sectional view of the piston rod of the present invention.

[0028] Figure 6 This is a cross-sectional view of the connecting piece of the present invention.

[0029] Figure 7 This is a schematic diagram of the connection between the cylinder front end cover, the cylinder rear end cover and the buffer component of the present invention.

[0030] Figure 8 This is a schematic diagram of the magnetic field distribution of the built-in permanent magnet of the present invention.

[0031] In the figure, 1-piston rod, 101-air outlet channel, 102-annular air inlet channel, 103-piston rod front end cover, 104-air supply hole, 105-piston rod front end sealing ring, 106-piston rod rear end sealing ring, 107-connector outer sealing groove, 108-connector inner sealing groove, 110-piston rod inner shaft, 120-piston rod outer shaft, 130-piston rod rear end component, 140-connector, 2-air floating piston, 201-throttling module, 202-axial airway, 203 -First annular pressure relief groove, 204-Second annular pressure relief groove, 205-First exhaust hole, 206-Small cavity, 207-Second exhaust hole, 3-Cylinder barrel, 301-Magnetic isolation sleeve, 4-Built-in permanent magnet, 401-Permanent magnet A, 402-Permanent magnet B, 5-Buffer component, 501-Front end cover buffer permanent magnet, 502-Front end buffer rubber ring, 503-Rear end cover buffer permanent magnet, 504-Rear end buffer rubber ring, 6-Cylinder front end cover, 7-Cylinder rear end cover, 8-Air bearing. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below with reference to the specific embodiments of the drawings, but the protection scope of the present invention is not limited thereto.

[0033] Figure 1 This is a schematic diagram of the structure of a permanent magnet eddy current damped air-floating frictionless pneumatic actuator according to the present invention. The actuator comprises a cylinder 3, an air-floating piston 2 located within the cylinder 3 with a gap between it and the inner wall of the cylinder 3, a piston rod 1 with one end extending into the air-floating piston 2, an internal permanent magnet 4 within the air-floating piston 2, a front end cover 6 and a rear end cover 7 disposed at each end of the cylinder 3, a buffer member 5 located on each of the front and rear ends of the cylinder 3 and facing the air-floating piston 2, and an air bearing 8 located between the piston rod 1 and the front end cover 6. Each of the front and rear ends of the cylinder 3 is provided with a vent hole connecting the outside world to the interior of the cylinder 3. Air is introduced through the vent hole on one of the front and rear ends of the cylinder 3, and exhausted through the vent hole on the other end, thereby enabling the air-floating piston 2 to move left or right within the cylinder 3, thereby enabling the piston rod 1 to move left or right. An air bearing 8 is provided between the piston rod 1 and the cylinder front end cover 6; the cylinder front end cover 6 is provided with radial holes for ventilating the air bearing 8, which are used to supply air into the air bearing 8 when the air bearing 8 is working.

[0034] like Figure 2-4As shown, the air-floating piston 2 is a cavity structure with an open end, and a number of throttling holes connecting the internal cavity of the air-floating piston 2 and the gap between the air-floating piston 2 and the inner wall of the cylinder 3 are evenly arranged along the side wall; the throttling hole is arranged on the throttling module 201, and the throttling module 201 is threadedly connected to the side wall of the air-floating piston 2, which facilitates the replacement of the throttling module 201 and can achieve different throttling hole sizes without reprocessing the air-floating piston 2; a number of blind holes that are not connected to the throttling hole are provided on the end face of the throttling module 201. In this embodiment, two blind holes are provided, which are respectively located on both sides of the throttling hole, so that tools such as tweezers can be used to insert into the two blind holes to facilitate screwing the throttling module 201 onto the air-floating piston 2 or removing the throttling module 201 from the air-floating piston 2. The side wall of the air-floating piston 2 is provided with several axial air passages 202 which are not connected to the throttle hole. The outside of the side walls at both ends of the air-floating piston 2 is respectively provided with a first annular pressure relief groove 203 and a second annular pressure relief groove 204. The inner wall of the end face of the air-floating piston 2 is provided with a small cavity 206. The bottom of the first annular pressure relief groove 203 is provided with a first exhaust hole 205 which is connected to the axial air passage 202. The bottom of the second annular pressure relief groove 204 is provided with a second exhaust hole 207 which is connected to the axial air passage 202 and the small cavity 206 in sequence. In this way, air circulation channels of the first annular pressure relief groove 203 → first exhaust hole 205 → axial air passage 202 → second exhaust hole 207 → small cavity 206 and the second annular pressure relief groove 204 → second exhaust hole 207 → small cavity 206 can be formed in the air-floating piston 2.

[0035] like Figure 5-6As shown, the piston rod 1 includes a piston rod outer shaft 120, a connector 140, and a piston rod rear end member 130, which are fixedly connected and detachable in sequence, and a piston rod inner shaft 110, which passes through the piston rod outer shaft 120 and the connector 140 and is fixedly connected and detachable to the piston rod rear end member 130. In this embodiment, the piston rod inner shaft 110 and the piston rod rear end member 130 are threadedly connected, and the two sides of the connector 140 are threadedly connected to the piston rod outer shaft 120 and the piston rod rear end member 130. A piston rod rear end sealing ring 106 is provided at the connection between the piston rod inner shaft 110 and the piston rod rear end member 130 to ensure sealing between the piston rod inner shaft 110 and the piston rod rear end member 130 and prevent gas leakage at the connection between the piston rod inner shaft 110 and the piston rod rear end member 130. An air outlet channel 101 extending axially to communicate with the small cavity 206 is provided within the piston rod inner shaft 110, and a radial air outlet is provided on the end of the piston rod inner shaft 110 away from the piston rod rear end member 130, connecting the air outlet channel 101 with the outside world. Gas in the air outlet channel 101 can be discharged through an external pipe connected to the radial air outlet, or the gas in the air outlet channel 101 can be discharged directly from the radial air outlet without an external pipe. In this way, an air outlet channel is formed in the piston rod 1, which goes from the small cavity 206 to the air outlet channel 101 to the radial air outlet. An annular air inlet channel 102 is formed between the piston rod inner shaft 110 and the piston rod outer shaft 120. A radial air inlet is provided on the end of the piston rod outer shaft 120 away from the piston rod rear end member 130, connecting the annular air inlet channel 102 with the outside world. Gas can be discharged into the annular air inlet channel 102 by connecting an external pipe to the radial air inlet. The piston rod inner shaft body 110 is configured in a stepped shape at the end away from the air-floating piston 2, and the shoulder thereof is an outer conical structure. A matching inner conical structure is provided on the piston rod outer shaft body 120 at a position corresponding to the outer conical structure on the piston rod inner shaft body 110, thereby achieving a conical fit. This ensures coaxiality between the piston rod inner shaft body 110 and the piston rod outer shaft body 120 when the piston rod inner shaft body 110 is connected to the piston rod rear end member 130. A piston rod front end sealing ring 105 is provided at the conical fit between the piston rod outer shaft body 120 and the piston rod inner shaft body 110 to ensure sealing at the conical fit between the piston rod outer shaft body 120 and the piston rod inner shaft body 110, thereby preventing gas in the annular air inlet passage 102 from leaking from the conical fit between the piston rod outer shaft body 120 and the piston rod inner shaft body 110.In addition, in the present invention, the piston rod inner shaft body 110 and the piston rod rear end member 130 are detachably fixedly connected, and the two sides of the connecting member 140 are detachably fixedly connected to the piston rod outer shaft body 120 and the piston rod rear end member 130, respectively. For example, a threaded connection is used, so that the outer diameter of the end of the piston rod inner shaft body 110 that extends into the piston rod outer shaft body 120 is smaller than the inner diameter of the piston rod outer shaft body 120. In this way, when the piston rod inner shaft body 110 axially extends into the piston rod outer shaft body 120, an annular air inlet channel 102 is naturally formed between the two, avoiding the need to process a long annular hole and facilitating production and processing. The connecting member 140 is provided with an air supply hole 104 that connects the annular air inlet channel 102 and the internal cavity of the air-floating piston 2. In this way, an air inlet channel is formed in the piston rod 1 in the order of radial air inlet → annular air inlet channel 102 → air supply hole 104 → the internal cavity of the air-floating piston 2. A piston front end cap 103 is fixed to the piston rod outer shaft 120 and is detachably connected to the open end of the air-floating piston 2. In this embodiment, the piston front end cap 103 is threadedly connected to the open end of the air-floating piston 2, which is used to install the piston rod outer shaft 120 on the air-floating piston 2 and simultaneously seal the open end of the air-floating piston 2. The piston rod 1 and the air-floating piston 2 form a total air intake channel: annular air intake channel 102 → air supply hole 104 → the internal cavity of the air-floating piston 2 → the throttle hole → the gap between the air-floating piston 2 and the inner wall of the cylinder 3. This also forms a total air outlet channel: the gap between the air-floating piston 2 and the inner wall of the cylinder 3 → the first annular pressure relief groove 203 → the first exhaust hole 205 → the axial air channel 202 → the second exhaust hole 207 → the small cavity 206 → the air outlet channel 101; and the gap between the air-floating piston 2 and the inner wall of the cylinder 3 → the second annular pressure relief groove 204 → the second exhaust hole 207 → the small cavity 206 → the air outlet channel 101. The present invention achieves frictionless operation by forming a high-pressure air film in the gap between the air-floating piston 2 and the inner wall of the cylinder 3, preventing direct contact between the air-floating piston 2 and the inner wall of the cylinder 3. The piston front end cap 103 is stepped and features an outer conical structure at the shoulder. A matching inner conical structure is provided at the corresponding position on the outer conical structure of the piston front end cap 103 at the open end of the air-floating piston 2, achieving a conical fit. This ensures the coaxiality of the piston rod 1 and the air-floating piston 2 when the piston front end cap 103 is installed on the open end of the air-floating piston 2.

[0036] The built-in permanent magnet 4 includes a permanent magnet A401 and a permanent magnet B402 respectively mounted on the piston rod outer shaft 120 and the piston rod rear end member 130, that is, the permanent magnet A401 and the permanent magnet B402 are respectively located on both sides of the connecting member 140, and the eddy current generated during the movement of the built-in permanent magnet 4 is used to absorb the vibration energy generated during the movement, thereby reducing vibration and improving the control accuracy of the pneumatic actuator. In addition, in the present invention, the two sides of the connecting member 140 are respectively detachably fixedly connected to the piston rod outer shaft 120 and the piston rod rear end member 130, such as by threaded connection. In this way, when installing the permanent magnet A401 and the permanent magnet B402, the permanent magnet A401 is first installed on the piston rod outer shaft 120, and then the connecting member 140 and the piston rod rear end member 130 are installed in sequence, and then the permanent magnet B402 is installed on the piston rod rear end member 130, thus completing the installation of the built-in permanent magnet 4; then the piston rod inner shaft 110 is axially rotated. The piston rod 1 extends through the outer shaft 120 and is mounted on the piston rod rear end member 130. The piston rod 1 is then mounted on the air-floating piston 2. This allows the built-in permanent magnet 4 to be integrated into the air-floating piston 2, preventing the built-in permanent magnet 4 from occupying additional space within the cylinder 3 and, in turn, preventing the built-in permanent magnet 4 from affecting the effective travel of the air-floating piston 2 within the cylinder 3. In other words, the piston rod 1 is configured as a detachable, split structure in the present invention, facilitating the installation of the built-in permanent magnet 4 onto the piston rod 1 and, in turn, facilitating the integration of the built-in permanent magnet 4 into the air-floating piston 2. The connector 140 is made of ferromagnetic material; the magnetic poles of the permanent magnets A401 and B402 are opposite. When the permanent magnets A401 and B402 are mounted on both ends of the connector 140, the connection between the permanent magnets A401, B402, and the connector 140 becomes more secure, while also enhancing the magnetic field to a certain extent. The outer ring of the cylinder 3 is equipped with a magnetic isolation sleeve 301; the magnetic isolation sleeve 301 is made of ferromagnetic material and is used to shield the magnetic field to avoid the influence of the outside world when the actuator is working, such as Figure 8 The figure shows the magnetic field distribution of the internal permanent magnet. The contact surface between the connector 140 and the internal permanent magnet 4 is provided with an outer sealing groove 107, and the contact surface between the connector 140 and the piston rod outer shaft 120 and the piston rod rear end member 130 is provided with an inner sealing groove 108. Sealing rings are provided on both the outer sealing groove 107 and the inner sealing groove 108 to ensure sealing between the connector 140 and the internal permanent magnet 4, and between the connector 140 and the piston rod outer shaft 120 and the piston rod rear end member 130.

[0037] The buffer device 5 includes a front cover buffer permanent magnet 501 and a rear cover buffer permanent magnet 503, respectively mounted on the cylinder front cover 6 and rear cover 7. The front cover buffer permanent magnet 501 has the same magnetic pole as permanent magnet A401 near one end of the front cover buffer permanent magnet 501, while the rear cover buffer permanent magnet 504 has the same magnetic pole as permanent magnet B402. One side of the front cover buffer permanent magnet 501 is concavely mated with the cylinder front cover 7, while one side of the rear cover buffer permanent magnet 503 is concavely mated with the cylinder rear cover 8. When the air-floating piston 2 moves to the sides of the cylinder barrel 3, the repulsive magnetic force between the permanent magnets provides a buffer, preventing the air-floating piston 2 from quickly colliding with the cylinder front cover 6 and rear cover 7. A front-end buffering rubber ring 502 and a rear-end buffering rubber ring 504 are respectively provided on the end surfaces of the front-end cover buffering permanent magnet 501 and the rear-end cover buffering permanent magnet 503, which are close to the built-in permanent magnet 4. This prevents the air-floating piston 2 from directly impacting the front-end cover buffering permanent magnet 501 and the rear-end cover buffering permanent magnet 503, thereby reducing damage to the front-end cover buffering permanent magnet 501 and the rear-end cover buffering permanent magnet 503 and extending their service life. Furthermore, the present invention can also adjust the buffering distance by changing the material or structural parameters of the front-end cover buffering permanent magnet 501 and the rear-end cover buffering permanent magnet 503, thereby adjusting the effective stroke of the pneumatic actuator.

[0038] The examples are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments. Any obvious improvements, substitutions or modifications that can be made by those skilled in the art without departing from the essence of the present invention are within the scope of protection of the present invention.

Claims

1. A permanent magnet eddy current damping air-floating frictionless pneumatic actuator, characterized by: The invention comprises a cylinder (3), an air-floating piston (2) located inside the cylinder (3), a piston rod (1) with one end extending into the air-floating piston (2), a built-in permanent magnet (4) located in the air-floating piston (2), a cylinder front end cover (6) and a cylinder rear end cover (7) arranged at both ends of the cylinder (3), and a buffer component (5) arranged opposite to the air-floating piston (2); the cylinder front end cover (6) and the cylinder rear end cover (7) are both provided with a vent hole connecting the outside with the internal cavity of the cylinder (3); The air-floating piston (2) is a cavity structure with an opening at one end, and a plurality of throttle holes are evenly arranged along the side wall to connect the internal cavity of the air-floating piston (2) and the gap between the air-floating piston (2) and the inner wall of the cylinder (3); a plurality of axial air passages (202) that are not connected to the throttle holes are arranged in the side wall of the air-floating piston (2); a first annular pressure relief groove (203) and a second annular pressure relief groove (204) are respectively arranged on the outer side walls of the two ends of the air-floating piston (2); a small cavity (206) is arranged on the inner wall of the end face of the air-floating piston (2); a first exhaust hole (205) connected to the axial air passage (202) is arranged at the bottom of the first annular pressure relief groove (203); a second exhaust hole (207) connected to the axial air passage (202) and the small cavity (206) is arranged at the bottom of the second annular pressure relief groove (204); The piston rod (1) comprises a piston rod outer shaft (120), a connecting piece (140) and a piston rod rear end member (130) which are detachably fixedly connected in sequence, and a piston rod inner shaft (110) which passes through the piston rod outer shaft (120) and the connecting piece (140) in sequence and is detachably fixedly connected to the piston rod rear end member (130); an air outlet passage (101) which extends axially to communicate with the small cavity (206) is provided in the piston rod inner shaft (110); the piston rod inner shaft (110) and the piston rod outer shaft An annular air inlet passage (102) is formed between the piston rod outer shaft (120), and an air supply hole (104) is provided in the connecting piece (140) for communicating with the annular air inlet passage (102) and the internal cavity of the air-floating piston (2); a piston front end cover (103) is fixed on the piston rod outer shaft (120) and is detachably connected to the open end of the air-floating piston (2); the built-in permanent magnet (4) includes a permanent magnet A (401) and a permanent magnet B (402) which are respectively sleeved on the piston rod outer shaft (120) and the piston rod rear end member (130); The buffer component (5) comprises a front cover buffer permanent magnet (501) and a rear cover buffer permanent magnet (503) respectively mounted on the cylinder front cover (6) and the cylinder rear cover (7); the front cover buffer permanent magnet (501) has the same magnetic pole as the permanent magnet A (401), and the rear cover buffer permanent magnet (503) has the same magnetic pole as the permanent magnet B (402).

2. The permanent magnet eddy current damping air-floating frictionless pneumatic actuator according to claim 1 is characterized in that: An air bearing (8) is provided between the piston rod (1) and the cylinder front end cover (6).

3. The permanent magnet eddy current damping air-floating frictionless pneumatic actuator according to claim 1 is characterized in that: The throttle hole is provided on the throttle module (201), the throttle module (201) is threadedly connected to the side wall of the air floating piston (2), and a plurality of blind holes not connected to the throttle hole are provided on the end surface of the throttle module (201).

4. The permanent magnet eddy current damping air-floating frictionless pneumatic actuator according to claim 1, characterized in that: A front end buffer rubber ring (502) and a rear end buffer rubber ring (504) are respectively provided on the front end cover buffer permanent magnet (501) and the rear end cover buffer permanent magnet (503).

5. The permanent magnet eddy current damping air-floating frictionless pneumatic actuator according to claim 1, characterized in that: The piston rod inner shaft (110) and the piston rod rear end member (130) are connected by threads; a piston rod rear end sealing ring (106) is provided at the connection between the piston rod inner shaft (110) and the piston rod rear end member (130); the connecting piece (140) and the piston rod outer shaft (120) and the piston rod rear end member (130) are connected by threads; and the piston front end cover (103) and the air floating piston (2) are connected by threads.

6. The permanent magnet eddy current damping air-floating frictionless pneumatic actuator according to claim 1, characterized in that: The piston front end cover (103) is stepped and has an outer conical structure at the shoulder. A matching inner conical structure is provided at a position corresponding to the outer conical structure on the piston front end cover (103) at one end of the opening of the air-floating piston (2).

7. The permanent magnet eddy current damping air-floating frictionless pneumatic actuator according to claim 1, characterized in that: The piston rod inner shaft (110) is arranged in a stepped shape at one end away from the air-floating piston (2) and has an outer conical structure at the shaft shoulder. A matching inner conical structure is provided on the piston rod outer shaft (120) at a position corresponding to the outer conical structure on the piston rod inner shaft (110) to achieve conical matching. A piston rod front end sealing ring (105) is provided at the conical matching position between the piston rod outer shaft (120) and the piston rod inner shaft (110).

8. The permanent magnet eddy current damping air-floating frictionless pneumatic actuator according to claim 1, characterized in that: The contact surface between the connecting member (140) and the built-in permanent magnet (4) is provided with an outer sealing groove (107), and the contact surface between the connecting member (140) and the piston rod outer shaft (120) and the piston rod rear end member (130) is provided with an inner sealing groove (108); sealing rings are provided on both the outer sealing groove (107) and the inner sealing groove (108).

9. The permanent magnet eddy current damping air-floating frictionless pneumatic actuator according to claim 1, characterized in that: The connecting member (140) is made of ferromagnetic material; the permanent magnet A (401) and the permanent magnet B (402) have opposing magnetic poles.

10. The permanent magnet eddy current damping air-floating frictionless pneumatic actuator according to claim 1, characterized in that: The outer ring of the cylinder (3) is equipped with a magnetic isolation sleeve (301); the material of the magnetic isolation sleeve (301) is ferromagnetic material.

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