Please select the most similar patent number from A, B, C and D. Which number is?
A ring-shaped permanently magnetic, low-frequency, vibration isolation mechanism based on the negative rigidity principle, comprising an upper rubber sheet (1), an inner ring-shaped permanent magnet stationary spindle (2), an upper pressing ring (3) of the upper rubber sheet, an outer pressing ring (4) of the upper rubber sheet, an outer ring-shaped permanent magnet (5), a lower rubber sheet (6), an inner pressing sheet (7) of the lower rubber sheet, an outer pressing ring (8) of the lower rubber sheet, an outer ring-shaped permanent magnet fixing sleeve (9), and an inner ring-shaped permanent magnet (10). The inner ring-shaped permanent magnet (10) is axially magnetized. The outer ring-shaped permanent magnet (5) is radially magnetized. The inner and outer ring-shaped permanent magnets form a positive rigidity system. The upper and lower rubber sheets form a negative rigidity system. The positive and negative rigidity systems are serially connected and used to form the low-frequency vibration isolation mechanism. Three or four single-degree-of-freedom isolation mechanisms can be serially connected to enable three-degrees-of-freedom low-frequency vibration isolation. The present invention can be applied in fields such as optics, acoustics, biology, semiconductor manufacturing, and precision measurement. The present invention is simple in structure, low in cost, easy to process, requires no external air source, and can be used in a vacuum.
A: The present invention relates to the field of ultra-precision vibration damping. A compact magnetic mechanism with negative rigidity, comprising a machine frame (1), a negative rigidity adjustment component, a flexible guide component, and a motion component. The magnetic mechanism with negative rigidity utilizes the repulsion action of reversely arranged magnets to form a negative rigidity property, and the negative rigidity can be adjusted by the negative rigidity adjusting component. An ultra-low frequency vibration damper formed by connecting the magnetic mechanism with negative rigidity and a positive rigidity spring (40) in parallel has an extremely low dynamic rigidity, thus greatly reducing the inherent frequency thereof, such that the vibration damper has a good vibration isolation effect for high frequency vibration interference while effectively isolating ultra-low frequency vibration, thus being suitable for a vibration sensitive ultra-precision machining and measurement device.
B: A radial permanent magnet floating bearing, comprising: a horizontal shaft (2), a support bearing (4), and a radial permanent magnet floating bearing (3); the permanent magnet floating bearing (3) comprises a stator pull-push magnet (31) disposed on a stator casing (1) via a magnetic substrate (322), and a rotor pull-push magnet (32) disposed on the horizontal shaft (2) correspondingly via an annular magnetic substrate (322), having a radial gap and forming an axial pull-push magnetic circuit with the stator pull-push magnet (31); the rotor pull-push magnet (32) consists of two or more annular permanent magnets axially and closely attached, with magnetic poles alternately arranged in the axial direction; the stator pull-push magnet (31) consists of two or more annular permanent magnets axially and closely attached, with magnetic poles alternately arranged in the axial direction, disposed over the horizontal panel where the axle center of the horizontal shaft (2) is located, and being symmetrical about the perpendicular bisection plane of the horizontal axis. The bearing has a simple structure and greatly reduces energy consumption, without wear or bearing maintenance.
C: The present invention relates to the field of magnetic valves. Disclosed is a high-power bi-directional non-recovery spring magnetic valve comprising permanent magnets. The magnetic valve comprising permanent magnets has an upper magnetic circuit part and lower magnetic circuit part symmetrically disposed and connected together via an armature connection rod (7) and a housing connection ring (14); the upper magnetic circuit part comprises an upper iron core (8), an upper housing (9), an upper coil (10), an upper annular permanent magnet (11), an upper yoke iron (12) and an upper push rod (13); the lower magnetic circuit part comprises a lower iron core (6), a lower housing (5), a lower coil (4), a lower annular permanent magnet (3), a lower yoke iron (2) and a lower push rod (1). The magnetic valve comprising permanent magnets realizes bistable-state magnetic retaining, and has an adjustable retaining force for permanent magnet adjustment, quick response, and high output force.
D: Disclosed is an axial permanent magnetic suspension bearing having micro-friction or no friction of the pivot point, comprising a support bearing (4) provided on a shaft serving as vertical, and a permanent magnetic suspension bearing (3) provided on the vertical shaft. The permanent magnetic suspension bearing (3) comprises a stator pull-push magnet (31) provided on a stator (1) and a rotor pull-push magnet (32) correspondingly provided on a rotor (2) by means of a soft magnetic material base (322) and axially separated from the stator pull-push magnet (31) to form a pull-push magnetic circuit. The stator pull-push magnet (31) and the rotor pull-push magnet (32) are respectively composed of two or more than two annular permanent magnets provided as radially closely fitting and with magnetic poles alternating in the radial direction, and upper and lower annular permanent magnets correspondingly in the same radial position have the same magnetic strength and inverse polarity. The stator pull-push magnet (31) and the rotor pull-push magnet (32) are radially spaced from the surface of the vertical shaft near an annular surface of the annular permanent magnets of the vertical shaft that is near the vertical shaft. The present invention has small magnets, is good to manufacture, is good to install, and has a high radial restoring force, while the force of attraction is great and frictional force is reduced by 98%.
Answer: A