Axial protection bearing pack for magnetic suspension main shaft

Abstract

An axial protection bearing pack for a magnetic suspension spindle is formed by two sets of angular contact ball bearings of the same model in a face-to-face pairing mode, each angular contact ball bearing is of a non-full complement rolling body retainer-free structure and comprises an outer ring, an inner ring and a rolling body, and the rolling body is arranged in a roller path between the outer ring and the inner ring. A molybdenum disulfide coating or a polytetrafluoroethylene coating is arranged on the inner diameter of the inner ring, an annular groove is formed in the outer end face of the inner ring, and an elastic damping piece protruding out of a notch is arranged in the annular groove. The protection bearing set can bear the instantaneous high impact capacity generated by the instantaneous high-speed performance of the magnetic suspension main shaft in the axial direction, and the magnetic suspension main shaft is effectively protected.

Description

Technical Field

[0001] The utility model relates to the technical field of bearings, in particular to an axial protection bearing group for a magnetic suspension main shaft. Background Art

[0002] The structure of the magnetic levitation spindle is complex and expensive. Once the rotor becomes unstable or the bearing loses power, the rotor will fall at an ultra-high speed and hit the stator under the impact force, causing damage to the magnetic bearing or even the spindle to be scrapped. The protective bearing is an important component of the magnetic levitation spindle. When the magnetic levitation system loses power or the control system fails, the rotor falls on the protective bearing at high speed. At this time, the protective bearing temporarily supports the high-speed rotating rotor to protect the equipment from damage. However, when the traditional protective bearing is used to protect the axial magnetic bearing of the magnetic levitation spindle, it is very easy to be damaged when subjected to large acceleration, ultra-high speed, huge vibration and impact, and cannot effectively protect the magnetic levitation spindle. Utility Model Content

[0003] In order to solve the above technical problems, the utility model provides an axial protection bearing group for a magnetic suspension spindle, which can withstand the instantaneous high impact capacity generated by the instantaneous high-speed performance of the magnetic suspension spindle from the axial direction, and effectively protect the magnetic suspension spindle.

[0004] In order to achieve the above technical purpose, the technical solution adopted is: an axial protection bearing group for a magnetic suspension spindle, which is composed of two sets of angular contact ball bearings of the same model that are matched face to face. The angular contact ball bearing adopts a non-full-filled rolling element and a cage-free structure. The angular contact ball bearing includes an outer ring, an inner ring and a rolling element. The rolling element is arranged in a raceway between the outer ring and the inner ring. The inner diameter of the inner ring is provided with a molybdenum disulfide coating or a polytetrafluoroethylene coating, and an annular groove is provided on the outer end surface of the inner ring. An elastic damping member protruding from the notch is provided in the annular groove.

[0005] The outer ring raceway and the inner ring raceway of the utility model are provided with a molybdenum disulfide coating or a polytetrafluoroethylene coating.

[0006] The thickness of the molybdenum disulfide coating or polytetrafluoroethylene coating described in the utility model is 0.02-0.05 mm.

[0007] The diameter of the rolling element in the utility model is D w , the average clearance S between two adjacent rolling elements satisfies: 0.08*D w ≤S≤0.16*D w .

[0008] The outer surface of the rolling body of the utility model is provided with a silver-plated layer, and the thickness of the silver-plated layer is 0.028mm-0.032mm.

[0009] The annular groove and the angular contact ball bearing of the utility model are coaxially arranged.

[0010] The annular groove depth h described in the utility model satisfies: h≤0.1B, the annular groove inner diameter d2 satisfies: d2≥d+0.3 (d1-d), and the annular groove outer diameter d3 satisfies: d3≤d1-0.2 (d1-d), wherein d is the inner ring diameter, d1 is the inner ring rib diameter, and B is the bearing inner ring width.

[0011] The elastic damping member of the utility model is composed of an annular spring and an annular damping strip. The annular spring and the annular damping strip are interference-fitted in an annular groove from inside to outside, and the annular damping strip protrudes from a notch of the annular groove.

[0012] The contact surface between the annular spring and the annular damping strip of the utility model is a conical surface.

[0013] The beneficial effects of the utility model are:

[0014] 1. The bearing group is composed of two sets of angular contact ball bearings of the same model matched face to face, which has stronger protection. The inner diameter of the inner ring is coated with molybdenum disulfide. The coating on the inner diameter of the inner ring can effectively prevent the magnetic suspension spindle rotor from sintering and adhering to the bearing, and can protect the rotor under normal operation to prevent rotor wear; an annular groove is arranged on the outer end face of the inner ring, and an elastic damping part is arranged on the annular groove. Before the rotor falls on the axial protection angular contact ball bearing group, it first contacts with the elastic damping part arranged on the end face of the inner ring. The elastic damping part and the protection bearing group work at the same time, which can timely avoid the protection bearing from vibration and impact, further improve the working speed of the protection bearing, and thus protect the magnetic suspension spindle.

[0015] 2. The partially filled silicon nitride rolling elements cooperate with the coatings on the outer ring raceways and the inner ring raceways to support the vertically falling rotor, and effectively prevent the bearing from getting stuck and sintered while reaching high-speed rotation in an instant.

[0016] 3. Adding a silver plating layer on the outer surface of the rolling element makes the bearing have certain self-lubricating properties and more suitable for high temperature environments, further preventing the bearing from getting stuck or sintered.

[0017] 4. Reasonably set the position and structure of the annular groove to increase the anti-collision effect without affecting the structural strength of the bearing itself.

[0018] 5. The elastic damping element is composed of a conical annular spring and a conical annular damping strip. After the magnetic suspension spindle is assembled with an axial protection angular contact ball bearing, when the magnetic suspension spindle rotor becomes unstable or the magnetic bearing loses power, two dampers with different damping characteristics absorb most of the axial vibration and impact. It is also possible to adjust the stiffness and damping coefficient of the elastic damping element by adjusting the two dampers, which can be adjusted by changing the contact surface angle. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the utility model;

[0020] In the figure: 1. Angular contact ball bearing;

[0021] 11. Outer ring, 12. Inner ring, 13. Rolling element;

[0022] 111. Outer ring raceway coating;

[0023] 121, annular groove, 122, elastic damping member, 123, inner ring raceway coating, 124, inner ring inner diameter coating;

[0024] 131. Rolling element coating;

[0025] 1221. annular spring. 1222. annular damping strip. DETAILED DESCRIPTION

[0026] The preferred embodiments of the utility model are given below in conjunction with the accompanying drawings to explain the technical solution of the utility model in detail. Here, the corresponding drawings will be given to explain the utility model in detail. It should be particularly noted that the preferred embodiments described here are only used to illustrate and explain the utility model, and are not used to limit or restrict the utility model.

[0027] In the description of this embodiment, the terms "inside", "outside", "front", "back", "left", "right", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They 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. Therefore, they should not be understood as limitations on the present invention.

[0028] like Figure 1As shown, an axial protection bearing group for a magnetic suspension spindle is formed by two sets of angular contact ball bearings 1 of the same model being matched face to face. The angular contact ball bearing 1 adopts a non-full-fill rolling element and a cage-free structure. The angular contact ball bearing 1 comprises an outer ring 11, an inner ring 12 and a rolling element 13. The rolling element 13 is arranged in a raceway between the outer ring 11 and the inner ring 12. After the axial protection bearing for the magnetic suspension spindle is assembled, when the magnetic suspension spindle rotor becomes unstable or the magnetic bearing loses power, the non-full-fill rolling element 13 cooperates with the outer raceway and the inner raceway to support the vertically falling rotor, and effectively prevents the bearing from being stuck and sintered while reaching high-speed rotation in an instant; the inner diameter of the inner ring 12 is provided with a molybdenum disulfide coating or a polytetrafluoroethylene coating, and the thickness of the molybdenum disulfide coating or the polytetrafluoroethylene coating is 0.02-0.05 mm. The inner diameter coating 124 of the inner ring can effectively prevent the magnetic suspension spindle rotor from sintering and adhering to the bearing. An annular groove 121 is provided on the outer end surface of the inner ring 12, and an elastic damping member 122 protruding from the notch is provided in the annular groove 121. The elastic damping member 122 works simultaneously with the protective bearing. The elastic damping member 122 protruding from the end surface of the bearing can withstand the impact before the bearing, and can timely prevent the protective bearing from vibration and impact, further improve the working speed of the protective bearing, and thus protect the magnetic suspension spindle. The elastic damping member 122 can be a damping strip with greater elasticity, such as rubber, or a spring steel with strong impact resistance and a certain elastic deformation force, such as a spring sheet.

[0029] The outer ring 11 raceway and the inner ring 12 raceway are provided with a molybdenum disulfide coating or a polytetrafluoroethylene coating, that is, the outer ring raceway coating 111 and the inner ring raceway coating 123 play a lubricating role to prevent the bearing from sintering, and the molybdenum disulfide coating or the polytetrafluoroethylene coating is provided by spraying or sputtering. The thickness of the molybdenum disulfide coating or the polytetrafluoroethylene coating is 0.02-0.05 mm.

[0030] In order to protect the bearing group and further prevent the bearing from being hit and stuck, the diameter of the rolling element 13 is set to D w , the average clearance S between two adjacent rolling elements 13 satisfies: 0.08*D w ≤S≤0.16*D w .

[0031] The outer surface of the rolling element 13 is provided with a silver-plated layer, and the thickness of the silver-plated layer, i.e., the rolling element coating 131, is 0.028 mm to 0.032 mm. The silver-plated layer plays a lubricating role. During normal operation, the silver-plated layer makes the use of the protective bearing group safer in a high temperature environment, and prevents the magnetic suspension spindle rotor from sintering and adhering to the bearing when the magnetic suspension system is powered off.

[0032] The annular groove 121 and the angular contact ball bearing 1 are coaxially arranged, so that the elastic damping member 122 in the annular groove 121 can fully contact the rotor in the axial direction when the rotor falls, so that the impact received is more balanced and the vibration and impact can be more reasonably endured.

[0033] The outer ring 11 and the inner ring 12 are made of high-strength steel, and the high-strength steel may be ZGCr15, which can be better used with the outer ring raceway coating 111 and the inner ring raceway coating 123. At the same time, the rolling element 133 is made of silicon nitride, which ensures the strength requirements for protecting the bearing and can better improve the ability to withstand impact force.

[0034] The depth h of the annular groove 121 satisfies: h≤0.1B, the inner diameter d2 of the annular groove 121 satisfies: d2≥d+0.3 (d1-d), and the outer diameter d3 of the annular groove 121 satisfies: d3≤d1-0.2 (d1-d), where d is the inner ring diameter, d1 is the inner ring rib diameter, and B is the bearing inner ring width. Reasonable setting of the size of the annular groove 121 can ensure the anti-impact strength of the installed elastic damping member without affecting the function of protecting the bearing itself.

[0035] The elastic damping member 122 is composed of an annular spring 1221 and an annular damping strip 1222. The damping coefficients and stiffness of the annular spring 1221 and the annular damping strip 1222 are different. The annular spring 1221 and the annular damping strip 1222 are installed in the annular groove 121 from the inside to the outside with interference fit. The annular damping strip 1222 protrudes from the notch of the annular groove 121. Through the two elastic damping members with different characteristics, when the annular damping strip 1222 is deformed by force, it compresses the annular spring 1221 to deform, absorbing most of the vibration and impact generated in the axial direction. The stiffness and damping coefficient of the elastic damping member can also be adjusted by adjusting the thickness of the annular spring 1221 and the annular damping strip 1222.

[0036] The contact surface between the annular spring 1221 and the annular damping strip 1222 is a conical surface, and the rigidity and damping coefficient of the elastic damping member 122 can be adjusted by changing the angle of the contact surface without changing the size of the annular groove or the size of the elastic damping member 122.

[0037] The above are only preferred examples of the present invention and are not intended to limit or restrict the present invention. For researchers or technicians in this field, the present invention may have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection declared by the present invention.

Claims

1. An axial protection bearing assembly for a magnetic suspension spindle, characterized in that: The invention relates to a bearing system comprising two sets of angular contact ball bearings (1) of the same model which are matched face to face. The angular contact ball bearings (1) adopt a non-full-fill rolling element and cage-free structure. The angular contact ball bearings (1) comprise an outer ring (11), an inner ring (12) and a rolling element (13). The rolling element (13) is arranged in a raceway between the outer ring (11) and the inner ring (12). The inner diameter of the inner ring (12) is provided with a molybdenum disulfide coating or a polytetrafluoroethylene coating. An annular groove (121) is provided on the outer end surface of the inner ring (12). An elastic damping member (122) protruding from the notch is provided in the annular groove (121).

2. The axial protection bearing assembly for a magnetic suspension spindle according to claim 1, characterized in that: The outer ring (11) raceway and the inner ring (12) raceway are provided with a molybdenum disulfide coating or a polytetrafluoroethylene coating.

3. An axial protection bearing assembly for a magnetic suspension main shaft according to claim 1 or 2, characterized in that: The thickness of the molybdenum disulfide coating or the polytetrafluoroethylene coating is 0.02-0.05 mm.

4. The axial protection bearing assembly for a magnetic suspension main shaft according to claim 1, characterized in that: The diameter of the rolling element (13) is D w , the average clearance S between two adjacent rolling elements (13) satisfies: 0.08*D w ≤S≤0.16*D w .

5. The axial protection bearing assembly for a magnetic suspension main shaft according to claim 1, characterized in that: The outer surface of the rolling element (13) is provided with a silver-plated layer, and the thickness of the silver-plated layer is 0.028 mm to 0.032 mm.

6. The axial protection bearing assembly for a magnetic suspension main shaft according to claim 1, characterized in that: The annular groove (121) and the angular contact ball bearing (1) are coaxially arranged.

7. The axial protection bearing assembly for a magnetic suspension main shaft according to claim 6, characterized in that: The depth h of the annular groove (121) satisfies: h≤0.1B, the inner diameter d2 of the annular groove (121) satisfies: d2≥d+0.3(d1-d), and the outer diameter d3 of the annular groove (121) satisfies: d3≤d1-0.2(d1-d), wherein d is the inner ring diameter, d1 is the inner ring rib diameter, and B is the bearing inner ring width.

8. The axial protection bearing assembly for a magnetic suspension main shaft according to claim 1, characterized in that: The elastic damping member (122) is composed of an annular spring (1221) and an annular damping strip (1222); the annular spring (1221) and the annular damping strip (1222) are interference-mounted in the annular groove (121) from the inside to the outside; the annular damping strip (1222) protrudes from a notch of the annular groove (121).

9. The axial protection bearing assembly for a magnetic suspension main shaft according to claim 8, characterized in that: The contact surfaces of the annular spring (1221) and the annular damping strip (1222) are conical surfaces.

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