Non-magnetic bearing, centerless fixture and method for manufacturing non-magnetic bearing

Abstract

The present invention provides a non-magnetic bearing, which relates to the technical field of bearings, and includes: an outer ring, an inner ring, a retainer and a ceramic ball, wherein a first groove is arranged on the circumference of the inner diameter center of the outer ring, and a second groove matching the first groove is arranged on the circumference of the outer diameter center of the inner ring, and the ceramic ball is fixed between the first groove and the second groove by the retainer, wherein the curvature coefficient of the first groove is greater than the curvature coefficient of the second groove, the curvature of the first groove is 0.525-0.510, and the curvature coefficient of the second groove is 0.515-0.505. The present invention improves the running trajectory of the ceramic ball along the normal direction of the contact between the ceramic ball and the outer ring by improving the inner ring and the outer ring to non-magnetic materials and lowering the curvature coefficients of the first groove of the outer ring and the second groove of the inner ring, thereby reducing the bearing vibration, and further reducing the noise generated by the vibration of the high-speed rotating wireless charging rotor. The present invention also provides a centerless fixture used for processing the above-mentioned non-magnetic bearing and a manufacturing method for the above-mentioned non-magnetic bearing.

Description

Technical Field

[0001] The present invention relates to the technical field of bearings, and more specifically, to a non-magnetic bearing, a centerless fixture and a method for manufacturing the non-magnetic bearing. Background Art

[0002] The promotion and use of electric vehicles has become one of the most concerned topics among the people. In order to promote the development of new energy vehicles and solve the problem that the connection and maintenance of wired charging lines are cumbersome and expensive, more and more companies have carried out technical research on wireless charging. The core principle is to use the electrode coupling principle for close-range wireless transmission. One of the coupling methods is that the terminal coupler rotates at high speed after being powered on, and couples with the other pole coupler paired with the high-speed rotating end, generating current after high-speed rotation. This generated current is one of the best choices for charging new energy vehicles.

[0003] The rotor supports at both ends of the coupler use deep groove ceramic ball non-magnetic bearings, because the bearings will not form eddy current effects and heat when the magnetic field is coupled, and will not generate energy consumption. However, after a large number of wireless charging systems were installed in underground garages, due to the poor structural design and manufacturing quality of deep groove ceramic ball non-magnetic bearings, the high-speed rotating wireless charging rotors will generate vibration noise, which directly affects the rest of the owners of the community and houses, and becomes a harmful sound source that disturbs the public. Summary of the invention

[0004] In order to solve the technical problem that after a large number of wireless charging systems are installed in garages, a high-speed rotating wireless charging rotor will generate vibration noise due to poor structural design and manufacturing quality of ceramic balls and inner and outer rings of deep groove ceramic ball non-magnetic bearings, the present invention provides a non-magnetic bearing, which is manufactured using non-magnetic materials, including: an outer ring, an inner ring, a retaining frame and ceramic balls, a first groove is arranged on the circumference of the inner diameter center of the outer ring, a second groove matching the first groove is arranged on the circumference of the outer diameter center of the inner ring, the ceramic balls are fixed between the first groove and the second groove through the retaining frame, wherein the curvature coefficient of the first groove is greater than the curvature coefficient of the second groove, and the curvature coefficient of the first groove is 0.525-0.510, and the curvature coefficient of the second groove is 0.515-0.505.

[0005] In some embodiments, a ratio of a curvature coefficient of the first groove to a curvature coefficient of the second groove is 1.016.

[0006] Furthermore, the curvature coefficient of the first groove is 0.515, and the curvature coefficient of the second groove is 0.507.

[0007] Optionally, the ceramic ball is made of silicon nitride material.

[0008] In some embodiments, the retainer includes a retainer beam, a plurality of pockets are provided on the retainer beam, and the inner diameter of the retainer is a cylindrical surface extending radially along the retainer body.

[0009] Furthermore, the diameter of the pocket is 1.0020 to 1.0030 times that of the ceramic ball.

[0010] Optionally, the cage is made of a polyetheretherketone composite material.

[0011] In some embodiments, the non-magnetic bearing further includes a sealing ring disposed between the inner ring and the outer ring and located on both sides of the ceramic ball, and the space enclosed by the sealing ring, the inner ring and the outer ring is filled with grease.

[0012] Furthermore, a flexible lip is arranged on the outer diameter surface of the sealing ring, the flexible lip is embedded in the sealing groove arranged on the outer ring, and the inner diameter surface of the sealing ring is clearance-matched with the inner ring.

[0013] Furthermore, a fourth groove is circumferentially arranged on the inner diameter surface of the sealing ring.

[0014] Furthermore, a fifth groove is provided on the circumference of one side of the sealing ring close to the ceramic ball.

[0015] In some embodiments, the inner ring and the outer ring are made of 40Mn material.

[0016] The present invention also provides a centerless clamp for fixing the inner ring or outer ring on the rotating positioning ring of the machine tool, a fixed seat for installing the supporting mechanism on the base of the machine tool headstock along the circumference of the rotating positioning ring; the supporting mechanism is arranged on the fixed seat, and the supporting mechanism includes two supporting points, and the two supporting points are used to support the inner ring or outer ring along the radial direction of the inner ring or outer ring and locate the position of the inner ring or outer ring on the rotating positioning ring, and the radial supporting directions of the two supporting points are at a preset angle; the pressing mechanism is used to press the inner ring or outer ring against the rotating positioning ring, and enable the inner ring or outer ring to rotate synchronously when the rotating positioning ring rotates.

[0017] Furthermore, the preset angle is a right angle.

[0018] In some embodiments, the support mechanism includes a first support assembly and a second support assembly, wherein one of the two support points is disposed on the first support assembly, and the other of the two support points is disposed on the second support assembly.

[0019] Furthermore, the first support assembly and the second support assembly each include a support portion and a fixing portion connected to the fixing seat, and the support portion is assembled on the fixing portion in an adjustable position along the radial support direction.

[0020] Optionally, the fixing portion includes a first slotted hole, the length direction of the first slotted hole is parallel to the radial supporting direction, and the supporting portion is assembled on the fixing portion by a first fixing member passing through the first slotted hole;

[0021] Optionally, one of the fixing portion and the supporting portion is provided with a slide rail, and the other of the fixing portion and the supporting portion is provided with a slide groove matching the slide rail, and the sliding direction of the supporting portion is parallel to the radial supporting direction.

[0022] In some embodiments, the fixing seat is detachably connected to the base.

[0023] Furthermore, the fixing seat is a cylindrical structure, a T-shaped groove is arranged in the circumferential direction of the upper end surface of the fixing seat, and the support mechanism is assembled on the fixing seat in an adjustable position by means of T-shaped bolts cooperating with the T-shaped groove.

[0024] In some embodiments, the pressing mechanism includes a pressing assembly and a driving assembly, and the pressing assembly is used to press the inner ring or the outer ring under the drive of the driving assembly.

[0025] Optionally, the pressure assembly includes a first bracket, a second bracket and two rollers for applying pressure to the inner ring or the outer ring, the two rollers are symmetrically arranged at the first end of the first bracket, the second end of the first bracket opposite to the first end is connected to the driving assembly, one end of the second bracket is fixed on the fixed seat, and the other end of the second bracket is hinged to the position between the first end and the second end of the first bracket.

[0026] Furthermore, the first bracket includes a connecting portion and a first support arm and a second support arm symmetrically arranged on the connecting portion, a roller is respectively arranged at the end of the first support arm and the second support arm away from the connecting portion, and the connecting portion is respectively hingedly connected to the second bracket and fixedly connected to the driving assembly.

[0027] Optionally, a second slot hole is provided on the connecting part, the length direction of the second slot hole is perpendicular to the extension direction of the first support arm or the second support arm, and the first support arm and the second support arm are adjustably assembled on the connecting part by a third fixing member passing through the second slot hole.

[0028] Optionally, the connecting part includes a first part and a second part, the first part is provided with a first support arm and a second support arm, the second part is respectively hingedly connected to the first bracket and fixedly connected to the drive assembly, and the first part is assembled on the second part in an adjustable position along the extension direction of the first support arm or the second support arm.

[0029] In some embodiments, the driving assembly includes a second bracket, a driving member and a connecting member with a spherical surface. The driving member is fixed to the fixed base through the second bracket. The connecting member is arranged between the driving member and the pressing assembly, and the spherical surface of the connecting member faces the pressing assembly.

[0030] Optionally, the driving member includes a sleeve, a screw and a spring. The sleeve is connected to the second bracket, the screw passes through the sleeve and is threadedly connected to the bottom layer of the sleeve, one end of the screw is fixedly connected to the connecting member, and the other end of the screw is the driving end. The spring is arranged in the sleeve and longitudinally sleeved on the screw, one end of the spring abuts against the connecting member, and the other end of the spring abuts against the bottom layer of the sleeve.

[0031] The present invention also provides a method for manufacturing a non-magnetic bearing, which uses the above-mentioned centerless fixture to process the inner ring or outer ring, including: providing a number of inner rings and outer rings formed by lathes; after rough-grinding the upper and lower end surfaces of the inner ring and the outer ring with a double-end surface grinder, rough-grinding the outer diameters of the inner ring and the outer ring with a centerless grinder, using an inner cylindrical grinder, an inner groove grinder and an outer groove grinder, and fixing the inner ring and the outer ring with a centerless fixture, and rough-grinding the inner diameter of the inner circle, the second groove of the inner ring and the first groove of the outer ring; treating the rough-ground inner ring and the outer ring with a combination of high-temperature nitriding and quenching to improve the strength, wear resistance and hardness of the ring; after fine-grinding the upper and lower end surfaces of the inner ring and the outer ring with a double-end surface grinder, fine-grinding the outer diameters of the inner ring and the outer ring with a centerless grinder, using an inner cylindrical grinder, an inner groove grinder and an outer groove grinder, and fixing the inner ring and the outer ring with a centerless fixture. The inner ring and outer ring are finely ground, the inner diameter of the inner ring, the second groove of the inner ring and the first groove of the outer ring are finely ground, and the inner ring and outer ring are supplemented with tempering after fine grinding; after supplementary tempering, the upper and lower end faces of the inner ring and outer ring are finely ground with an end face fine grinding machine, the outer diameters of the inner ring and outer ring are finely ground with a centerless grinder, and the outer diameters of the inner ring and outer ring are finely ground with an outer diameter fine grinding machine, and then the inner circle grinder, the inner groove grinder and the outer groove grinder are fixed with a centerless fixture, and the inner diameter of the inner ring, the second groove of the inner ring and the first groove of the outer ring are finely ground; finally, the inner groove super-finishing machine and the outer groove super-finishing machine are used to fix the inner ring and the outer ring with a centerless fixture, and the second groove of the inner ring and the first groove of the outer ring are super-finished; after the grinding process is completed, cleaning and sorting are carried out, and the retainer and ceramic balls are installed between the inner ring and the outer ring.

[0032] The ceramic balls are spaced apart by cages.

[0033] Optionally, providing the inner ring and outer ring formed by numerical turning specifically includes: subjecting the 40Mn material bar to solid solution treatment and aging treatment, and then to machine tool processing to obtain the outer ring and inner ring formed by numerical turning.

[0034] Optionally, the solution treatment is to keep the 40Mn rod at 1020° C. to 1060° C. for 15 min to 40 min and then quickly cool it; and / or the aging treatment is to keep the 40Mn rod at 520° C. to 560° C. for 3 h to 4 h.

[0035] Optionally, the high temperature nitriding treatment is to maintain the inner ring and the outer ring at 1000° C.-1060° C. for 20 min to 40 min in a nitrogen atmosphere after rough grinding.

[0036] Optionally, the outer ring and the inner ring are subjected to tempering treatment as follows: the finely ground outer ring and the inner ring are tempered at 140-150° C. for 3 h to 5 h.

[0037] Since the hardness of the ceramic ball is greater than that of the steel ball, the elastic modulus is more than 1.5 times that of the steel ball, and the Poisson is smaller, the present invention improves the running trajectory of the ceramic ball along the normal direction of the contact between the ceramic ball and the outer ring by lowering the curvature coefficient of the first groove of the outer ring and the second groove of the inner ring, thereby reducing the vibration of the bearing and further reducing the noise generated by the vibration of the high-speed rotating wireless charging rotor. At the same time, since the curvature coefficient of the first groove of the outer ring and the second groove of the inner ring is lowered, the contact area of ​​the ceramic ball with the first groove and the second groove is increased when the ceramic ball rotates at high speed, thereby reducing the contact stress between the ceramic ball and the inner and outer rings, and improving the service life of the non-magnetic bearing.

[0038] At the same time, if Figure 8 As shown, by using the centerless clamp provided by the present invention, the adverse effect of the radial runout of the machine tool spindle on the machining accuracy of the inner ring, outer ring groove and inner diameter of the inner ring of the grinder is avoided, and at the same time, the technical problem of excessive positioning errors of the inner ring and outer ring caused by the clamping deformation of the workpiece using a conventional spring chuck is eliminated, thereby improving the machining accuracy, meeting the machining design requirements of the non-magnetic bearing, and thereby reducing the noise generated by the vibration of the high-speed rotating wireless charging rotor.

[0039] By using the preparation method of the non-magnetic bearing provided by the present invention, the dimensional accuracy, shape and position tolerance, surface roughness, and bearing vibration noise of the processed inner and outer rings all reach a pass rate of more than 98%, and there is a certain accuracy reserve. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0041] Figure 1 A schematic diagram of the structure of a non-magnetic bearing provided in an embodiment of the present invention;

[0042] Figure 2 for Figure 1 The schematic diagram of the outer ring structure shown;

[0043] Figure 3 for Figure 1 The schematic diagram of the inner ring structure shown;

[0044] Figure 4 for Figure 1 A front view of the retainer in the radial direction shown;

[0045] Figure 5 for Figure 1A cross-sectional view of a single pocket of the cage shown perpendicular to the radial direction;

[0046] Figure 6 for Figure 1 The schematic diagram of the sealing ring structure shown;

[0047] Figure 7 A schematic diagram of the structure of a centerless fixture provided in an embodiment of the invention;

[0048] Figure 8 for Figure 7 A top view of the centerless fixture shown;

[0049] Fig. 9 for Figure 8 A schematic structural diagram of the first supporting assembly;

[0050] Reference numerals

[0051] exist Figure 1-Figure 5 In the middle, 20-inner ring, 10-outer ring, 11-first groove, 21-second groove, 12-sealing groove, 30-ceramic ball, 40-cage, 50-sealing ring, 57-grease, 41-cage lintel, 42-pocket hole;

[0052] exist Figure 6 In the figure, 51-flexible lip, 52-fourth groove, 53-fifth groove, 54-skeleton, 55-outer diameter surface, 56-inner diameter surface, 511-wedge angle, 512-third groove;

[0053] exist Figure 7 Among them, 61-base, 62-fixed seat, 621-T-slot, 70-support mechanism, 80-pressing mechanism, 81-pressing assembly, 811-first bracket, 82-driving assembly, 821-third bracket, 822-driving member, 8221-sleeve, 8222-spring, 8223-screw, 823-connecting member, 833-shaft, 813-roller, 812-second bracket, 843-wrench, 844-eccentric disk, 91-rotating positioning ring, 93-spindle;

[0054] exist Figure 8 Among them, 71-first support assembly, 72-second support assembly, 8112-first support arm, 8113-second support arm, 813-roller, 621-T-slot, 62-fixed seat, 814-third fixing member, 8111-connecting part, 81111-first part, 81112-second part, 81113-second slot, 823-connecting member, 92-grinding wheel;

[0055] exist Fig. 9 Among them, 74-fixing part, 741-first slot hole, 73-supporting part, 76-first fixing piece, 75-T-bolt, 621-T-slot. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0057] Embodiment 1

[0058] The embodiment of the present invention provides a non-magnetic bearing, which is made of non-magnetic materials, such as Figure 1 As shown, it includes: an outer ring 10, an inner ring 20, a retaining frame 40 and ceramic balls 30.

[0059] A first groove 11 is provided on the circumference of the inner diameter center of the outer ring 10, and a second groove 21 cooperating with the first groove 11 is provided on the circumference of the outer diameter center of the inner ring 20. It should be noted that the inner diameter center of the outer ring 10 here refers to the center of the inner diameter surface, and the outer diameter center of the inner ring 20 refers to the center of the outer diameter surface. Figure 2-3 As shown, the outer ring 10 and the inner ring 20 are made of non-magnetic materials, such as Fe-Mn-Cr-C series austenitic stainless steel materials. Optionally, the outer ring 10 and the inner ring 20 are made of 40Mn, which is basically non-magnetic in the solid solution state. When the external magnetic field strength is 15920A / m, the maximum magnetic permeability μ max =1.006×10 -6 H / m, with the same speed characteristics as bearing steel. This material has good cutting and grinding performance. After heat treatment, the bearing ring can obtain high hardness, high wear resistance, good fatigue resistance and toughness. The first groove 11 is arranged on the inner diameter circumference of the outer ring 10, and the first groove 11 is arranged at the center of the inner diameter. The second groove 21 is arranged on the outer diameter circumference of the inner ring 20 to match the first groove 11, and the second groove 21 is arranged at the center of the outer diameter. A ceramic ball 30 is arranged between the first groove 11 and the second groove 21, and the movement of the ceramic ball 30 in the radial direction perpendicular to the inner ring 20 or the outer ring 10 can be limited except for the matching gap.

[0060] The ceramic balls 30 are evenly spaced between the first groove 11 and the second groove 21 through the retaining frame 40. Specifically, Figure 1As shown, the ceramic ball 30 is made of zirconium oxide (ZRO2) or silicon nitride (SI3N4). The ceramic ball 30 has oil-free self-lubricating properties, and the friction coefficient of the ceramic ball 30 is small, so the ceramic ball bearing has a very high rotation speed. Optionally, the ceramic ball 30 is made of silicon nitride material, which is characterized by 0.4 times the density of the bearing steel ball, 2.5 times the hardness of the bearing steel ball, and less than a quarter of the linear expansion coefficient of the steel ball. Therefore, when working at high speed, the use of ceramic balls instead of steel balls presents small inertial centrifugal force, small friction resistance and friction torque, low heat generation, low bearing operation temperature rise, low temperature rise causes small change in the clearance of the bearing mating surface, and the radial clearance of the bearing tends to be stable, which reflects that the bearing's operation accuracy and operation characteristics are very excellent. Further, the spherical error of the ceramic ball 30 is less than 0.1μm, the average surface roughness Ra is less than 0.005μm, and the average single particle vibration value is less than 31dB. The groove diameters of the first groove 11 of the outer ring 10 and the second groove 21 of the inner ring 20 and the radial clearance of the ceramic ball 30 are 0.006MM to 0.015MM.

[0061] The retainer 40 is used to cooperate with the first groove 11 and the second groove 21 to arrange the ceramic balls 30 equidistantly between the inner ring 20 and the outer ring 10. Specifically, Figure 4-5 As shown, the cage 40 includes a cage beam 41 and a plurality of pockets 42 arranged on the cage beam 41. The inner diameter of the cage 40 is a cylindrical surface extending radially along the cage beam 41. The number of pockets 42 is equal to the number of ceramic balls 30. The cage 40 is made of wear-resistant and high-temperature resistant materials, such as polyetheretherketone composite materials. Its density is 1.51, which is one-fifth of that of the steel cage 40. Under the statutory load, its contact stress is one-fourth of that of the steel cage 40. It has a small friction coefficient and good high and low temperature resistance, and can adapt to the working temperature rise of -55℃ to 200℃. Optionally, the polyetheretherketone composite material can be a polyetheretherketone-based glass fiber composite material or a polyetheretherketone-based graphite composite material. Further, the diameter of the pocket 42 is 1.0020 to 1.0030 times the diameter of the ceramic ball 30. Optionally, the diameter of the pocket 42 is 1.0025 times the diameter of the ceramic ball 30. Compared with steel balls, reducing the diameter of the pockets 42 can match the pockets 42 with the low expansion coefficient of the ceramic balls 30, and can further reduce the displacement of the ceramic balls 30 along the circumference of the cage 40, thereby further reducing the vibration of the rotor under high-speed rotation and reducing the noise generated by the high-speed rotation of the rotor. Experiments have shown that the cage 40 made of polyetheretherketone-based glass fiber composite material has a smaller friction coefficient than other metal and coated cages.

[0062] In this embodiment, the curvature coefficient of the first groove 11 is greater than that of the second groove 21, wherein the curvature coefficient of the first groove 11 is 0.525-0.510, and the curvature coefficient of the second groove 21 is 0.515-0.505. Optionally, the curvature coefficient of the first groove 11 is 0.515, and the curvature coefficient of the second groove 21 is 0.507.

[0063] Furthermore, the ratio of the curvature coefficient of the first groove 11 to the curvature coefficient of the second groove 21 is 1.016.

[0064] In conventional deep groove ball bearings, the curvature coefficient of the groove of the outer ring 10 is generally 0.530, and the curvature coefficient of the groove of the inner ring 20 is generally 0.520, and the steel ball can reach equal contact stress with the outer ring 10 and the inner ring 20. However, due to the low expansion coefficient of the ceramic ball 30 and the small Poisson, under the conventional coefficient, the contact area between the ceramic ball 30 and the inner ring 20 and the outer ring 10 is small, which will produce displacement in the normal direction. Therefore, when the rotor rotates, the vibration will be larger. In this embodiment, by lowering the curvature coefficient of the first groove 11 to be greater than the curvature coefficient of the outer ring 10, so that it matches the Poisson of the ceramic ball 30, the running track of the ceramic ball 30 along the normal direction is improved, which is conducive to reducing the bearing vibration. At the same time, since the running track of the ceramic ball 30 along the normal direction is improved, the contact stress between the ceramic ball 30 and the inner ring 20 and the outer ring 10 remains unchanged, which improves the life of the non-magnetic bearing. Experiments show that when the bearing speed is higher than 15000r / min, the service life of the non-magnetic bearing provided in this embodiment is 1.5 to 2 times higher than that of the steel ball bearing. The outer ring 10 and the inner ring 20 of the non-magnetic bearing are matched with the ceramic ball 30, which can not only enhance the bearing's ability to bear loads, but also enable the bearing to play the advantages of the ceramic ball being light in weight, having a low friction coefficient, and having many advantages of increasing the speed during high-speed operation, so the combination of the two can achieve complementary advantages.

[0065] Embodiment 2

[0066] This embodiment provides a non-magnetic bearing, which, in addition to the non-magnetic bearing provided in the first embodiment, further includes a sealing ring 50 disposed between the inner ring 20 and the outer ring 10 and located on both sides of the ceramic ball 30 .

[0067] There are two sealing rings 50, and the space enclosed by the two sealing rings 50, the inner ring 20 and the outer ring 10 is filled with grease 57, thereby increasing the life of the bearing and preventing the rotor from vibrating under high-speed rotation. Figure 1 and Figure 6As shown, the sealing ring 50 can be made of nitrile rubber, butyl rubber or EPDM rubber. Optionally, the sealing ring 50 is made of EPDM. A flexible lip 51 is provided on the outer diameter surface 55 of the sealing ring 50, and the inner diameter surface 56 of the sealing ring 50 is matched with the outer diameter clearance of the inner ring 20. A sealing groove 12 is provided circumferentially on the inner diameter of the outer ring 10, and the sealing groove 12 is located on both sides of the first groove 11. The flexible lip 51 can be embedded in the sealing groove 12, and then the sealing ring 50 is limited between the inner ring 20 and the outer ring 10. The side of the flexible lip 51 close to the ceramic ball 30 has a wedge angle 511, and the wedge angle 511 is conducive to the sealing ring 50 being stuck into the sealing groove 12. Furthermore, a third groove 512 is provided on the side of the flexible lip 51 away from the ceramic ball 30. The cross-section of the third groove 512 is trapezoidal, semicircular, etc., which is not limited here. The third groove 512 increases the flexibility of the flexible lip 51 , and thus the third groove 512 facilitates the flexible lip 51 to shrink along the radial direction of the sealing ring 50 when the sealing ring 50 is installed.

[0068] The lubricating grease 57 is filled in the space surrounded by the sealing ring 50, the inner ring 20 and the outer ring 10. Figure 1 As shown, the lubricating grease 57 can reduce the friction between the ceramic ball 30, the inner ring 20, the outer ring 10 and the retaining frame 40. When the bearing speed is 15000-20000 r / min, the lubricating grease 57 is preferably a synthetic lubricating grease with a ratio of 30%-40%.

[0069] Further, such as Figure 6 As shown, the inner diameter surface 56 of the sealing ring 50 is circumferentially provided with a fourth groove 52, which can store more grease 57 to prevent the grease 57 from overflowing. At the same time, the friction between the sealing ring 50 and the outer diameter of the inner ring 20 is reduced, and the sealing performance of the sealing ring 50 is improved. The fourth groove 52 is arranged in the middle position of the inner diameter surface 56 of the sealing ring. The cross section of the fourth groove 52 is approximately semi-elliptical.

[0070] Further, such as Figure 6 As shown, the sealing ring 50 also includes a fifth groove 53, which is arranged on the circumference of one side of the sealing ring 50 close to the ceramic ball 30. The cross section of the fifth groove 53 is a trapezoid, a semicircle, etc., which is not limited here. The fifth groove 53 is used to store grease 57 and increase the flexibility of the overall structure of the sealing ring 50. The depth of the fifth groove 53 is determined according to actual needs.

[0071] Optionally, in order to enhance the strength of the sealing ring 50, as Figure 6 As shown, a skeleton 54 can be provided in the sealing ring 50. The skeleton 54 can be made of a high-hardness elastic material such as stainless steel.

[0072] In this embodiment, a sealing ring 50 is provided between the inner ring 20 and the outer ring 10 to protect the grease in the bearing from being polluted by external dust and impurities. At the same time, the friction between the ceramic ball 30, the inner ring 20 and the outer ring 10 is reduced, thereby improving the life of the non-magnetic bearing.

[0073] Embodiment 3

[0074] Conventional groove processing of the outer ring or inner ring of bearing steel is to fix the outer ring or inner ring on the rotating positioning ring 91 of the machine tool through an electromagnetic fixture, and then grind it with a grinding wheel 92. However, since the outer ring 10 and the inner ring 20 are made of non-magnetic materials, electromagnetic chucks cannot be used. At the same time, due to the influence of the radial runout of the spindle 93 on the use of spring chucks, it is difficult to ensure the processing accuracy of the first groove 11 of the outer ring 10 and the second groove 21 of the inner ring, as well as the inner diameter of the inner ring during the grinding process. As a result, the manufacturing quality of non-magnetic bearings is poor and cannot meet the quality requirements of non-magnetic bearings.

[0075] After repeated research, the embodiment of the present invention also designs and manufactures a centerless fixture for fixing the inner ring or the outer ring on the rotating positioning ring 91 of the machine tool, such as Figure 7 , Figure 8 and Fig. 9 As shown, it includes a fixed seat 62, a pressing mechanism 80 and a supporting mechanism 70; the fixed seat 62 is used to install the supporting mechanism 70 on the base 61 of the machine tool head along the circumference of the rotating positioning ring; the supporting mechanism 70 is arranged on the fixed seat 62, and the supporting mechanism 70 includes two supporting points 731, and the two supporting points 731 are used to support the inner ring or outer ring along the radial direction of the inner ring or outer ring and locate the position of the inner ring or outer ring on the rotating positioning ring 91, and the supporting directions of the two supporting points are at a preset angle. After being positioned radially by the two supporting points, the pressing mechanism 80 presses the inner ring or outer ring tightly against the rotating positioning ring 91, and allows the inner ring or outer ring to rotate synchronously when the rotating positioning ring 91 rotates, wherein the supporting direction is Figure 8 A direction.

[0076] The fixing seat 62 is used to fix the support mechanism 70 on the machine tool head base 61 and is arranged along the circumference of the rotating positioning ring 91. The fixing seat 62 can be arranged around the entire rotating positioning ring 91, or can be arranged at a fixed point according to the position where the workpiece needs to be supported during the processing, which is not limited here. Figure 7 , Fig. 9 As shown, the fixing seat 62 is detachably assembled on the base 61. Further, a T-slot 621 is provided on the circumference of the upper end surface of the fixing seat 62, and the support mechanism 70 is fixed on the fixing seat 62 by a T-bolt 75 matched with the T-slot 621. By adjusting the setting position of the support mechanism 70 on the circumference of the fixing seat 62 to adapt to workpieces of different sizes, the application range of the centerless fixture is improved.

[0077] The support mechanism 70 is disposed on the fixed seat 62. The two support points 731 support the workpiece along the radial direction of the inner ring or the outer ring. The support directions of the two support points 731 are at a preset angle, and the preset angle can be an obtuse angle, a right angle or an acute angle. For example, the preset angle is 30° to 180° (excluding 180°). In other words, the support directions of the two support points are not linear. Optionally, the preset angle is a right angle. The support points 731 are two protrusions on the support mechanism 70. Specifically, as Fig. 9 As shown, the support mechanism includes a first support assembly 71 and a second support assembly 72. One of the two support points 731 is set on the first support assembly 71, and the other of the two support points 731 is set on the second support assembly 72. The first support assembly 71 and the second support assembly 72 can be fixed in the T-slot 621 of the fixing seat 62 by T-bolts 75.

[0078] Further, such as Fig. 9 As shown, the first support assembly 71 and the second support assembly 72 each include a support portion 73 and a fixing portion 74 connected to the fixing seat 62, and the support portion 73 is assembled on the fixing portion 74 in an adjustable position along the support direction. Screw holes are provided on the fixing surface where the fixing portion 74 is connected to the fixing seat 62, and the fixing portion 74 is fixed to the fixing seat 62 by T-bolts. Further, the support point 731 of the support portion 73 is made of cemented carbide, and the optional material is silicon nitride or zirconium oxide ceramic, so as to prevent the processing deviation of the support point 731 of the support portion 73 caused by wear.

[0079] As a feasible implementation method, Fig. 9 As shown, the fixing portion 74 includes a first slotted hole 741, the length direction of the first slotted hole 741 is parallel to the radial support direction, and the support portion 73 is assembled on the fixing portion 74 by passing through the first fixing member 76 of the first slotted hole 741. By adjusting the position of the first fixing member 76 in the slotted hole, the relative distance between the support portion 73 and the workpiece along the radial support direction is adjusted to meet the processing requirements of different workpieces. At the same time, by adjusting the support positions of the first support assembly 71 and the second support assembly 72, the positioning accuracy of the workpiece is ensured. Specifically, a screw hole is set on the support portion 73, and the first fixing member 76 is a bolt. By loosening the bolt, adjusting the position of the support portion 73 in the first slotted hole 741, and then tightening the bolt, the support portion 73 is fixed.

[0080] As another feasible implementation, one of the fixed portion 74 and the supporting portion 73 is provided with a slide rail, and the other of the fixed portion 74 and the supporting portion 73 is provided with a slide groove cooperating with the slide rail, and the sliding direction of the supporting portion 73 is parallel to the radial support direction, which can also realize the technical function of the first slot hole 741 technical solution.

[0081] In some embodiments, Figure 7 and Figure 8As shown, the pressing mechanism 80 includes a pressing assembly 81 and a driving assembly 82 . The pressing assembly 81 is used to press the inner ring or the outer ring under the drive of the driving assembly 82 .

[0082] In some embodiments, the pressing assembly 81 includes a first bracket 811, a second bracket 812 and two rollers 813 for applying pressure to the inner ring or the outer ring. Two rollers 813 are symmetrically arranged at the first end of the first bracket 811, the second end of the first bracket 811 opposite to the first end is connected to the driving assembly 82, and the position between the first end and the second end of the first bracket is hinged to the second bracket 812. Optionally, the pressing assembly may also include a shaft 833, the shaft 833 is arranged below the first bracket 811, the top end of the second bracket 812 is connected to the tail of the shaft 833 by a hinge, and the head of the shaft 833 is connected to the driving assembly 82. It should be noted that the spacing between the two rollers 813 is equivalent to the diameter of the workpiece to be processed, so that when the roller 813 is pressed on the upper end surface of the workpiece, the rolling direction of the roller 813 is parallel to the tangential direction of the workpiece rotation, which can reduce the wear of the roller 813. At the same time, the height of the processed workpiece can be adjusted by replacing the second bracket 812.

[0083] Specifically, the first bracket 811 includes a connecting portion 8111 and a first support arm 8112 and a second support arm 8113 vertically arranged on the connecting portion 8111. The first support arm 8112 and the second support arm 8113 are each provided with a roller 813 at the end away from the connecting portion 8111. The connecting portion 8111 is respectively hinged to the second bracket 812 and fixedly connected to the driving assembly 82. The first support arm 8112 and the second support arm 8113 form an approximate Y shape with the connecting portion 8111.

[0084] Optional, such as Figure 8 As shown, the connecting portion 8111 is provided with a second slotted hole 81113, the length direction of the second slotted hole 81113 is perpendicular to the extension direction of the first support arm 8112 or the second support arm 8113, and the first support arm 8112 and the second support arm 8113 are assembled on the connecting portion 8111 with adjustable spacing through the third fixing member 814 passing through the second slotted hole 81113. Specifically, two second slotted holes 81113 are respectively provided at the positions where the first support arm 8112 and the second support arm 8113 are installed on the connecting portion 8111, and screw holes are provided at corresponding positions of the first support arm 8112 and the second support arm 8113. The third fixing member 814 is a bolt, and the spacing between the first support arm 8112 and the second support arm 8113 is adjusted according to the size of the workpiece, and then the first support arm 8112 and the second support arm 8113 are fixed to the connecting portion 8111 through the third fixing member 814 via the first support arm 8112 and the second support arm 8113.

[0085] Optional, such as Figure 8As shown, the connecting portion 8111 may also include a first portion 81111 and a second portion 81112, wherein the first portion 81111 is provided with a first support arm 8112 and a second support arm 8113, and the second portion 81112 is respectively hinged to the first bracket 811 and fixedly connected to the driving assembly 82, and the first portion 81111 is positionally adjustable and assembled on the second portion 81112 along the extension direction of the first support arm 8112 or the second support arm 8113. Specifically, a screw hole is provided on the first portion 81112, and a suitable mounting hole is selected according to the size of the workpiece, and the first portion 81111 is fixed to the second portion 81112 with a bolt. It should be noted that a third slotted hole may also be provided on the first portion 81111, and the mounting position of the first portion 81111 on the second portion 81112 is adjusted by the third slotted hole, which is not specifically limited here.

[0086] In some embodiments, the driving assembly 82 includes a third bracket 821, a driving member 822, and a connecting member 823 having a spherical surface. The driving member 822 is fixed to the fixing seat 62 through the third bracket 821. The connecting member 823 is disposed between the driving member 822 and the pressing assembly 81, and the spherical surface of the connecting member 823 faces the pressing assembly 81. Specifically, as Figure 7 As shown, the driving member 822 includes a sleeve 8221, a screw 8223 and a spring 8222. The sleeve 8221 is connected to the third bracket 821. The screw 8223 passes through the sleeve 8221 and is threadedly connected to the bottom layer of the sleeve 8221. One end of the screw 8223 is fixedly connected to the connecting member 823. The other end of the screw 8223 is the driving end. The spring 8222 is arranged in the sleeve 8221 and is longitudinally sleeved on the screw 8223. One end of the spring 8222 abuts against the connecting member 823, and the other end of the spring 8222 abuts against the bottom layer of the sleeve 8221. Furthermore, the driving end of the screw 8223 is connected to the eccentric disk 844 on the machine tool, and a wrench 843 is provided on the eccentric disk 845. The screw 8223 can be pulled by the wrench 843 and the eccentric disk 844 to move the screw 8223 forward and backward. When the screw 8223 moves backward, the spring 8222 is in a compressed state. At this time, the roller 813 of the pressing assembly 81 is in a Figure 7 The workpiece is disengaged outward from the position shown, so that the processed ferrule can be removed, and another ferrule is installed on the support mechanism 70, and the machine tool wrench 843 is loosened to restore the free state by the spring. Even if the roller 813 of the pressing assembly 81 presses the workpiece, the grinding process can be performed at the position shown. It should be noted that the screw 8223 and the connecting member 823 can be an integral structure or a split structure, which is not limited here. When the screw 8223 and the connecting member 823 are a split structure, the two can be detachably connected, and the specific connection method can be a threaded connection, etc.

[0087] This embodiment takes the processing of the first groove of the outer ring as an example to illustrate the use of the centerless fixture:

[0088] First, place the outer ring on the positioning ring that rotates concentrically with the main shaft 93, and then adjust the two support points so that the center of the outer ring slightly deviates from the center of the main shaft 93, that is, the center of the outer ring is located in the first quadrant. After the relative positions of the first support assembly 71 and the second support assembly 72 are adjusted, the downward pressure structure 80 moves downward and applies pressure to the upper end surface of the outer ring through the roller 813. When the outer ring rotates on the support of the first support assembly 71 and the second support assembly 72, friction will be generated. At the same time, the outer ring has its own gravity. When the outer ring rotates eccentrically, torque will be generated. When grinding the workpiece, there will be grinding resistance. However, whether the outer ring is idling or in the grinding state, the combined force direction of the above forces is always toward the middle of the two support points, commonly known as the clamping force. Therefore, under the action of the clamping force, the outer ring will rotate stably on the two support points, so the grinding process can also be carried out normally.

[0089] In this embodiment, the eccentric torque generated by the rotation of the workpiece is exactly located in the middle position of the two supporting points 731 of the supporting mechanism 70, so that the workpiece produces a clamping force, thereby achieving stable rotation of the workpiece, and stable grinding can be performed at the same time. This solves the problem that the non-magnetic bearing cannot use an electromagnetic chuck and uses a centering spring chuck to produce radial runout of the spindle 93, which causes poor processing accuracy of the workpiece. At the same time, when the centerless clamp provided by this embodiment supports and clamps the workpiece, since the two radial supports have no clamping force, and the axial clamping is clamped by the roller and the workpiece under the state of relative rotation and sliding friction, the clamping force is very small and controllable, so there is no problem of clamping deformation of the workpiece. Therefore, it improves the positioning accuracy of the workpiece, and then ensures that the workpiece can obtain a higher processing accuracy.

[0090] Embodiment 4

[0091] This embodiment provides a method for manufacturing a non-magnetic bearing, comprising:

[0092] S110, provides machined inner and outer rings;

[0093] Specifically, after the 40Mn material bar is subjected to solution treatment and aging treatment, the 40Mn bar is formed by numerical turning to obtain the numerically turned inner ring and outer ring with a Rockwell hardness (HRC) of 28 to 43.

[0094] Furthermore, the solution treatment condition is to heat the machined outer ring to 1020℃~1060℃ and keep it for 15min~40min and then cool it quickly. Preferably, the solution treatment time is 20min; the aging treatment condition is to keep it at 520℃~560℃ for 3h~4h. After aging treatment, the alloy elements are dissolved into the solid solution, thereby enhancing the toughness, impact resistance and fatigue resistance of the ring, thereby improving the service life of the non-magnetic bearing.

[0095] S120, after rough grinding the upper and lower end surfaces of the outer ring on a double-end surface grinder, rough grinding the outer diameters of the inner ring and the outer ring with a centerless grinder, using an internal grinder, an inner groove grinder, and an outer groove grinder, using the centerless fixture to fix the inner ring and the outer ring, and rough grinding the inner diameter of the inner ring, the first groove of the inner ring, and the first groove of the outer ring;

[0096] S130, the inner and outer rings after rough grinding are treated with high temperature nitriding and quenching to improve the strength, wear resistance and hardness of the rings;

[0097] Specifically, the high-temperature nitriding condition is to maintain the temperature above 1000°C in a nitrogen atmosphere for half an hour. After high-temperature nitriding and quenching, the outer ring and inner ring with a Rockwell hardness HRC of 62-64 are obtained, that is, the strength, wear resistance and hardness of the inner ring and outer ring are improved. In this embodiment, since the melting point of 40Mn material is relatively high, a higher temperature can be used during high-temperature nitriding, which greatly reduces the time of high-temperature nitriding and improves production efficiency.

[0098] S140, after fine grinding the upper and lower end surfaces of the inner ring and the outer ring with a double end surface grinder, fine grinding the outer diameters of the inner ring and the outer ring with a centerless grinder, using an internal grinder, an inner groove grinder, and an outer groove grinder, using the centerless fixture to fix the inner ring and the outer ring, fine grinding the inner diameter of the inner ring, the second groove of the inner ring, and the first groove of the outer ring, and performing additional tempering treatment on the inner ring and the outer ring after fine grinding;

[0099] Specifically, the supplementary tempering treatment is a supplementary tempering treatment at 140-150° C. for 3-5 hours.

[0100] S150, after the additional tempering, the upper and lower end faces of the inner ring and the outer ring are finely ground with an end face fine grinding machine, the outer diameters of the inner ring and the outer ring are finely ground with a centerless grinder, the outer diameters of the inner ring and the outer ring are finely ground with an outer diameter fine grinding machine, the inner circle grinder, the inner groove grinder and the outer groove grinder are used, the inner ring and the outer ring are fixed with the centerless fixture, the inner diameter of the inner ring, the second groove of the inner ring and the first groove of the outer ring are finely ground, the inner groove superfinishing machine and the outer groove superfinishing machine are used, the inner ring and the outer ring are fixed with the centerless fixture, and the second groove of the inner ring and the first groove of the outer ring are superfinished;

[0101] S170, sorting and assembling the sleeves after cleaning, installing a retaining frame and ceramic balls between the inner ring and the outer ring, and the ceramic balls are separated by the retaining frame.

[0102] Specifically, the outer ring and the inner ring are cleaned with an ultrasonic cleaning machine, and after the sizes of the first groove and the second groove are sorted, the cage is placed in the middle, and the qualified ceramic balls are loaded into the cage between the first groove of the outer ring and the second groove of the inner ring. After the assembly, the radial clearance is checked to ensure that the first groove of the outer ring, the second groove of the inner ring and the selected ceramic ball match in size.

[0103] Furthermore, the non-magnetic bearing further includes a sealing ring, and the manufacturing method of the non-magnetic bearing further includes:

[0104] S180, install the sealing ring on one side of the ceramic ball and the cage;

[0105] S190, use a grease injection machine to quantitatively load grease;

[0106] S200, install the sealing ring on the other side of the ceramic ball and cage;

[0107] S210, use a fat homogenizer to homogenize the fat.

[0108] After the above steps, the finished non-magnetic bearings are inspected for radial clearance, inner diameter runout, outer diameter runout, inner ring end face runout, bearing vibration velocity and vibration acceleration vibration values. Non-magnetic bearings that meet the requirements are packed and stored after rust-proof treatment.

[0109] As shown in Table 1, through the non-magnetic bearing preparation method provided in this embodiment, the processed inner ring and outer ring have reached 100% qualification in terms of dimensional accuracy, form and position tolerance, surface roughness, bearing vibration and noise, and have a certain accuracy reserve, which shows that the determination and arrangement of the optimized processing technology is reasonable.

[0110] Table 1. Parameters of the non-magnetic bearing produced by the non-magnetic bearing manufacturing method provided in this embodiment.

[0111]

[0112]

[0113] In the description of the present invention, it should be understood that the so-called "connection" and "coupling", unless otherwise specified, include direct and indirect connections.

[0114] In the description of the present invention, it is necessary to understand that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0115] Although the embodiments disclosed in the present invention are as above, the contents described are only embodiments adopted to facilitate understanding of the present invention and are not intended to limit the present invention. Any technician in the field to which the present invention belongs can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A centerless fixture for fixing the inner ring or outer ring of a non-magnetic bearing on a rotating positioning ring of a machine tool, characterized in that: It includes a fixing seat, a pressing mechanism and a supporting mechanism; The fixing seat is used to mount the supporting mechanism on the base of the machine tool headstock along the circumference of the rotating positioning ring; The support mechanism is arranged on the fixed seat, and the support mechanism includes two support points, and the two support points are used to support the inner ring or the outer ring along the radial direction of the inner ring or the outer ring and locate the position of the inner ring or the outer ring on the rotating positioning ring, and the support directions of the two support points are at a preset angle; The pressing mechanism is used to press the inner ring or the outer ring onto the rotating positioning ring, so that the inner ring or the outer ring can rotate synchronously when the rotating positioning ring rotates; The pressing mechanism comprises a pressing assembly and a driving assembly, wherein the pressing assembly is used to press the inner ring or the outer ring under the drive of the driving assembly; The pressing assembly comprises a first bracket, a second bracket and two rollers for applying pressure to the inner ring or the outer ring, the two rollers are symmetrically arranged at the first end of the first bracket, the second end of the first bracket opposite to the first end is connected to the driving assembly, one end of the second bracket is fixed to the fixing seat, and the other end of the second bracket is hinged to the position between the first end and the second end of the first bracket; The driving assembly comprises a third bracket, a driving member and a connecting member having a spherical surface, wherein the driving member is fixed to the fixing seat through the third bracket, the connecting member is arranged between the driving member and the pressing assembly, and the spherical surface of the connecting member faces the pressing assembly; The driving member includes a sleeve, a screw and a spring. The sleeve is connected to the third bracket. The screw passes through the sleeve and is threadedly connected to the bottom layer of the sleeve. One end of the screw is fixedly connected to the connecting member, and the other end of the screw is the driving end. The spring is arranged in the sleeve and longitudinally sleeved on the screw. One end of the spring abuts against the connecting member, and the other end of the spring abuts against the bottom layer of the sleeve.

2. The centerless fixture according to claim 1, characterized in that: The preset angle is a right angle.

3. The centerless fixture according to claim 1, characterized in that: The support mechanism includes a first support assembly and a second support assembly, wherein one of the two support points is arranged on the first support assembly, and the other of the two support points is arranged on the second support assembly.

4. The centerless fixture according to claim 3, characterized in that: The first support assembly and the second support assembly each include a support portion and a fixing portion, the fixing portion is connected to the fixing seat, and the support portion is assembled on the fixing seat in an adjustable position along the radial direction.

5. The centerless fixture according to claim 4, characterized in that: The fixing portion comprises a first slot, the length direction of the first slot is parallel to the supporting direction, and the supporting portion is assembled on the fixing portion by a first fixing member passing through the first slot. Alternatively, a slide rail is provided on one of the fixing portion and the supporting portion, and a slide groove cooperating with the slide rail is provided on the other of the fixing portion and the supporting portion, and the sliding direction of the supporting portion is parallel to the radial supporting direction.

6. The centerless fixture according to any one of claims 1 to 5, characterized in that: The fixing seat is detachably connected to the base.

7. The centerless fixture according to any one of claims 1 to 5, characterized in that: The fixing seat is a cylindrical structure, and a T-shaped slot is arranged in the circumferential direction of the upper end surface of the fixing seat. The support mechanism is assembled on the fixing seat in an adjustable manner through T-shaped bolts matched with the T-shaped slot.

8. The centerless fixture according to claim 1, characterized in that: The first bracket includes a connecting portion and a first support arm and a second support arm vertically arranged on the connecting portion, and a roller is respectively arranged at the end of the first support arm and the second support arm away from the connecting portion, and the connecting portion is respectively hinged to the second bracket and fixedly connected to the driving assembly.

9. The centerless fixture according to claim 8, characterized in that: A second slot hole is provided on the connecting portion, the length direction of the second slot hole is perpendicular to the extension direction of the first support arm or the second support arm, and the first support arm and the second support arm are assembled on the connecting portion with an adjustable spacing through a third fixing member passing through the second slot hole.

10. The centerless fixture according to claim 8, characterized in that: The connecting portion includes a first part and a second part, the first part is provided with the first support arm and the second support arm, the second part is respectively hinged to the first bracket and fixedly connected to the driving assembly, and the first part is assembled on the second part in an adjustable position along the extension direction of the first support arm or the second support arm.

11. A method for manufacturing a non-magnetic bearing, characterized in that: The inner ring and the outer ring are processed by the centerless fixture according to any one of claims 1 to 10, comprising: Provide inner and outer rings formed by multiple lathes; After the upper and lower end surfaces of the outer ring are roughly ground on a double-end surface grinder, the outer diameters of the inner ring and the outer ring are roughly ground on a centerless grinder, and the inner diameter of the inner ring, the second groove of the inner ring, and the first groove of the outer ring are roughly ground using an internal grinder, an inner groove grinder, and an outer groove grinder, and the inner ring and the outer ring are fixed with the centerless fixture. The inner and outer rings after rough grinding are treated by high temperature nitriding and quenching to improve the strength, wear resistance and hardness of the rings; After fine grinding the upper and lower end surfaces of the inner ring and the outer ring with a double end surface grinder, fine grinding the outer diameters of the inner ring and the outer ring with a centerless grinder, using an internal cylindrical grinder, an inner groove grinder and an outer groove grinder, and fixing the inner ring and the outer ring with the centerless fixture, fine grinding the inner diameter of the inner ring, the second groove of the inner ring and the first groove of the outer ring, and performing supplementary tempering treatment on the inner ring and the outer ring after fine grinding; After the additional tempering, the upper and lower end faces of the inner ring and the outer ring are ground with an end face grinding machine, the outer diameters of the inner ring and the outer ring are ground with a centerless grinder, the outer diameters of the inner ring and the outer ring are ground with an outer diameter grinding machine, the inner circle grinder, the inner groove grinder and the outer groove grinder are used, the inner ring and the outer ring are fixed with the centerless fixture, the inner diameter of the inner ring, the second groove of the inner ring and the first groove of the outer ring are ground, the inner groove superfinishing machine and the outer groove superfinishing machine are used, the inner ring and the outer ring are fixed with the centerless fixture, and the second groove of the inner ring and the first groove of the outer ring are superfinished; After cleaning, the sleeves are sorted and assembled, and a retaining frame and ceramic balls are installed between the inner ring and the outer ring. The ceramic balls are separated by the retaining frame.

12. The method for manufacturing a non-magnetic bearing according to claim 11, characterized in that: The inner and outer rings formed by several lathes include: The 40Mn material bar is subjected to solution treatment and aging treatment, and then is formed by multiple turning to obtain multiple turning outer rings and inner rings.

13. The method for manufacturing a non-magnetic bearing according to claim 12, characterized in that: The solution treatment is to keep the 40Mn rod at 1020°C to 1060°C for 15min to 40min and then quickly cool it; and / or the aging treatment is to keep the 40Mn rod at 520°C to 560°C for 3h to 4h.

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