CN114700870B

CN114700870B - Contact type ultra-precise chemical mechanical polishing device and method for bearing ring

Info

Publication number: CN114700870B
Application number: CN202210197054.6A
Authority: CN
Inventors: 江亮; 黄朝蓬; 钱林茂; 张韶华; 周宁宁; 陈宇
Original assignee: Southwest Jiaotong University
Current assignee: Southwest Jiaotong University
Priority date: 2022-03-01
Filing date: 2022-03-01
Publication date: 2023-01-31
Anticipated expiration: 2042-03-01
Also published as: CN114700870A

Abstract

The invention discloses a contact type ultra-precise chemical mechanical polishing device and a method for a bearing ring, wherein the polishing device comprises a first aligning module, a second aligning module, a sample rotating module, a sample clamping module, a polishing module and a machine base; the second aligning module adjusts the position of the sample clamping module, drives a ferrule on the sample clamping module to enable the ferrule to be coaxial with the sample rotating module, and the first aligning module adjusts the position of the polishing module to drive a polishing head on the polishing module to enable the polishing head to be coaxial with the ferrule. The polishing head rotates at a high speed to polish, the sample rotates at a low speed to homogenize errors, and the ultra-precision polishing of the ferrule is realized in a matching manner. The chemical mechanical polishing solution comprises 0.01 to 40 weight percent of colloidal silica, 0 to 10 weight percent of hydrogen peroxide, the balance of water and the pH value of 2 to 11. The invention designs the polishing head and the clamp of the inner and outer ring with pertinence; controlling the rotating speed of the sample rotating module and the polishing module, homogenizing errors and realizing the uniform polishing of the surface of the ferrule; the polishing solution is designed for stainless bearing steel, so that the nano-scale surface roughness is realized.

Description

Contact type ultra-precise chemical mechanical polishing device and method for bearing ring

Technical Field

The invention relates to the technical field of ultra-precision machining, in particular to a contact type ultra-precision chemical mechanical polishing device and method for a bearing ring.

Background

The bearing is an important part in mechanical equipment, and the main function of the bearing is to support the rotating mechanism, reduce the friction coefficient and ensure the rotation precision. With the rapid development of scientific technology, bearings are gradually applied to high-end equipment in the fields of aerospace, mechanical manufacturing, rail transit and the like, harsh lubrication states such as the thickness of a lubricating film is sharply reduced and the like are very likely to occur when the bearings work under extreme working conditions such as high and low temperatures, ultrahigh vacuum, high specific load, high and low speeds, repeated starting and stopping and the like, and if the roughness of the surfaces of the bearings is large, the thickness of the lubricating film is smaller than the height of rough peaks, the rough peaks are in direct contact with each other, the surfaces of the bearings are abraded, and the service performance and the service life of the bearings are influenced. Therefore, the technical requirements of high-end equipment are met by continuously breaking through the aspects of materials, design, manufacture, test and the like and ensuring the excellent service performance of the bearing.

From the perspective of bearing manufacturing, it is necessary to develop a new ultra-precision machining technique, improve the machining precision, reduce the surface roughness, improve the film thickness ratio (the ratio of the thickness of the lubricating oil film to the surface roughness), avoid direct contact between the surface roughness peaks of the friction pair, and achieve a good lubrication state, thereby improving the service performance and the service life of the bearing, and finally ensuring stable and reliable operation of the equipment. According to the references (Hiroki Komata, yasuhiro Iwanaga, tohru Ueda, koji Ueda, nobuaki Mitamura, enhanced Performance of Rolling Bearings by Improporting the Resistance of Rolling Elements to Surface Degradation, in: J.M. Beswick (Ed.) Bearing Steel Technologies: 10th Volume, advances in Steel Technologies for Rolling Bearings, ASTM International, west Consolon, PA, 2015, pp. 272-290), when the raceway roughness of the outer race is 30 nm and the raceway of the inner race is 50 nm, the Surface roughness of the ball is reduced from 209 nm to 6 nm and the life (flaking) of the Bearing is increased by about 5 times. It is concluded that the bearing ring and the rolling elements act as a pair of friction pairs, reducing the surface roughness of either or both, which is beneficial for improving the service performance and life of the bearing.

Currently, bearing rings are usually finished by oilstone honing, where the surface roughness can be reduced to below 100 nm. In order to further improve the bearing machining precision and reduce the surface roughness, some novel ultra-precision machining methods, such as electrochemical grinding, magnetorheological polishing, force rheological polishing, etc., are proposed, however, in the practical application process, the methods have the following disadvantages:

1) The magnetorheological polishing and the mechanical rheological polishing both adopt a pure mechanical scribing mode to remove the surface material of the bearing, the contact pressure needs to reach the plastic yield limit of the material during the removal, the minimum removal thickness is limited, and the surface quality of the bearing is difficult to further improve;

2) The force rheological polishing mainly realizes the thickening effect of the polishing solution by improving the shearing rate, however, for a curved surface, the relative speeds of all positions are different, the factors influencing the processing uniformity of all parts of the curved surface are more, the control is difficult, and the difficulty in improving the surface accuracy is greater.

The concept of chemical mechanical polishing was first proposed by mendelian corporation of usa in 1965, and then international business machines corporation of usa continuously perfects the chemical mechanical polishing process, and has been widely used in the manufacture of very large scale integrated circuits through decades of development. The chemical mechanical polishing can realize the sub-nanometer surface roughness and the nanometer surface type precision, the surface defect close to zero and the altered layer thickness close to zero on the silicon slice plane and the like through the synergistic action of chemical reaction and mechanical force. In view of the technical advantages of chemical mechanical polishing, the chemical mechanical polishing is organically combined with the traditional ultra-precision machining method, and a plurality of novel ultra-precision machining methods are developed and applied to bearing ultra-precision machining.

The invention discloses a device and a method for polishing a micro-bearing core element by ultra-precision flexible chemical mechanical polishing (patent number ZL202010118552.8, authorization date: 26/2/2021) in a Chinese patent authorized by the research group, and discloses the device and the method for polishing the micro-bearing core element by ultra-precision flexible chemical mechanical polishing, which can realize the ultra-precision processing of the surface of the core element and the conformal processing of a complex curved surface by optimizing the synergistic action of chemical reaction and mechanical force-rheological effect. However, in practical applications, the method has the following disadvantages:

1) The flexible chemical mechanical polishing solution of the method uses the polyhydroxy polymer as the non-Newtonian fluid for shear thickening, and the polyhydroxy polymer may react with other chemical reagents in the polishing solution to influence the polishing effect;

2) As mentioned above, the shear thickening polishing is mainly realized by impacting the surface of the bearing core element with the polishing solution at a high speed, however, for the core elements such as the bearing ring and the rolling element, the factors influencing the processing uniformity of each part of the curved surface of the element are more, the control is difficult, and the difficulty in improving the surface accuracy is greater.

As mentioned above, the device and the method for ultra-precision polishing of the bearing ring are designed, various problems existing in the existing ultra-precision machining are solved, and the device and the method have great significance for guiding the ultra-precision machining of the bearing ring.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a contact type ultra-precise chemical mechanical polishing device and a contact type ultra-precise chemical mechanical polishing method for a bearing ring, which comprise the following steps:

a bearing ring contact type ultra-precise chemical mechanical polishing device comprises: the device comprises a first aligning module, a second aligning module, a sample rotating module, a sample clamping module, a polishing module and a base; the sample rotating module and the first aligning module are arranged on the base respectively, the polishing module is arranged on the first aligning module, the second aligning module is arranged on the sample rotating module, the sample clamping module is arranged on the second aligning module, the second aligning module is used for driving the sample clamping module to move in the horizontal direction, so that a bearing ring on the sample clamping module is coaxial with the sample rotating module, the first aligning module is used for driving the polishing module to move in the horizontal direction and the vertical direction, so that a polishing head on the polishing module is coaxial with the bearing ring, the sample rotating module is used for driving the second aligning module to rotate, the sample clamping module rotates along with the second aligning module, so that the bearing ring is driven to rotate, the sample clamping module is used for clamping the bearing ring by pertinently providing a clamp, and the polishing module is used for polishing the bearing ring by pertinently providing a polishing head.

Further, the first aligning module comprises a motor frame, a first supporting rod, a second supporting rod and an opening fixing ring; the bottom of the second support rod is provided with a cylindrical hole, a cylindrical rod of the machine base is inserted into the cylindrical hole, the cylindrical rod is fixedly connected through a bolt, the first support rod is positioned on the second support rod, one end, far away from the motor frame, of the first support rod is provided with a first connecting plate, one end, far away from the machine base, of the second support rod is provided with a second connecting plate in matched connection with the first connecting plate, hole grooves are formed in the first connecting plate and the second connecting plate, the first connecting plate moves along the hole grooves relative to the second connecting plate, the first support rod moves in the horizontal direction relative to the second support rod, the motor frame is fixedly connected through the bolt after the position of the motor frame is adjusted, the motor frame is positioned on the first support rod and can move in the vertical direction along the first support rod, after the position of the motor frame is adjusted, an opening fixing ring arranged on the motor frame is used for fixing the position of the motor frame, and the motor frame is ensured to be horizontal.

Further, the second aligning module includes: the two-dimensional workbench comprises an upper positioning hole, a lower positioning hole, a first direction knob with scales and a second direction knob; the two-dimensional workbench moves towards the first direction and the second direction by rotating the two first direction knob control consoles with scales, the two directions are mutually perpendicular, the positions of the sample clamping modules can be determined by the scales on the knobs, a plurality of upper positioning holes are formed in the table top of the two-dimensional workbench and are used for fixing the sample clamping modules, four lower positioning holes are formed in the lower portion of the two-dimensional workbench and are used for fixing the two-dimensional workbench on the sample rotating modules through screws, the two-dimensional workbench rotates along with the sample rotating modules and drives the sample clamping modules to rotate, the lower rotating speed is set, the problem of uneven stress on the surface of a bearing ring caused by the machining errors of a polishing head is solved, the homogenization errors are reduced, and the high surface type precision of the bearing ring is ensured.

Further, the sample holding module comprises: the polishing device comprises a bearing ring clamp, a polishing solution pool and a cushion block; the polishing solution liquid pool is used for containing polishing solution and a clamp for fixing the bearing ring, the polishing solution liquid pool is fixed in a circular groove on the cushion block, the inner diameter of the circular groove is the same as the outer diameter of the polishing solution liquid pool, on the basis, the polishing solution liquid pool and the cushion block are fixedly connected through pins, the liquid pool is limited to rotate relative to the cushion block, the cushion block is fixedly connected onto the second aligning module through the pins and moves and rotates along with the second aligning module, after polishing is finished, the positioning pins are taken down, the cushion block is taken out, the sample clamping module is moved downwards, the bearing ring is separated from the polishing head, and the bearing ring is taken out.

Further, the bearing ring clamp includes: a bearing outer ring clamp and a bearing inner ring clamp; the bottom of the bearing outer ring clamp is provided with a disc base with the outer diameter the same as the inner diameter of a polishing solution pool, a cylinder which is coaxial with the disc base is arranged above the disc base, a stepped hole which is coaxial with the cylinder is formed in the cylinder, the inner diameter of the upper part of the stepped hole is slightly larger than the outer diameter of the bearing outer ring, so that the bearing outer ring can be conveniently placed in the cylinder, the upper part of the stepped hole is provided with four threaded holes, the bearing outer ring is tightly fixed through screwing screws to prevent the bearing outer ring from rotating, the inner diameter of the lower part of the stepped hole is smaller than the outer diameter of the bearing outer ring and larger than the inner diameter of the bearing outer ring, so that the bearing outer ring is kept at a specific height, meanwhile, the whole inner surface of the bearing outer ring is conveniently polished by the bearing polishing head, and four notches are uniformly formed around the cylinder to facilitate the entering of polishing solution; the bottom of the bearing inner ring clamp is a disc base with the same outer diameter and the same inner diameter of a polishing solution pool, a stepped shaft coaxial with the disc base is arranged above the disc base, the diameter of the upper portion of the stepped shaft is the same as the inner diameter of the bearing inner ring, the bearing inner ring is arranged on the upper portion of the stepped shaft through interference fit, the diameter of the lower portion of the stepped shaft is larger than the inner diameter of the bearing inner ring and smaller than the outer diameter of the bearing inner ring, the bearing inner ring is kept at a specific height, and meanwhile the polishing head is convenient to polish the whole outer surface of the bearing inner ring.

Further, the polishing module comprises: a polishing head, a motor and a motor controller; the polishing head consists of a substrate and a polishing pad, wherein the polishing pad is adhered to the surface of the substrate, the substrate and the polishing pad are both made of flexible materials, the substrate is made of silica gel, rubber or silicon rubber, and the polishing pad is made of polyurethane, wool, cow leather or nylon.

Further, the polishing head includes: a polishing head of the bearing outer ring and a polishing head of the bearing inner ring; the substrate of the polishing head of the outer bearing ring is a cylinder, the upper part of the polishing head is provided with a cylinder hole with the inner diameter being the same as the outer diameter of the motor shaft and a key groove, and the outer diameter of the cylinder is the same as the inner diameter of the outer bearing ring after the polishing pad is adhered to the outer surface of the cylinder; the substrate of bearing inner race polishing head is the cylinder, and upper portion has a diameter and the same cylinder hole of motor shaft external diameter, and subsidiary keyway, and the lower part has a cylinder hole, and behind the cylinder downthehole surface adhesion polishing pad, the internal diameter is the same with bearing inner race external diameter.

Furthermore, the motor is fixed in the center of the motor frame, the polishing head is connected to the motor shaft through a key, the motor reaches different rotating speeds by adjusting the motor controller, the polishing head is driven to rotate, higher rotating speed is set, and the bearing ring is polished under the combined action of the polishing pad and the chemical mechanical polishing solution.

Further, the polishing method by using the contact type ultra-precise chemical mechanical polishing device for the bearing ring provided by the invention comprises the following steps:

s1, fixedly installing a second aligning module on a sample rotating module, installing a bearing ring on a sample clamping module, fixedly installing the sample clamping module on the second aligning module, sequentially installing a first aligning module and a polishing module, and respectively adjusting the positions of a polishing head and the bearing ring through the first aligning module and the second aligning module to enable the polishing head, the bearing ring and the sample rotating module to be coaxial;

s2, preparing chemical mechanical polishing solution, uniformly stirring, and pouring into a polishing solution pool;

s3, setting polishing process parameters including environment temperature, rotation speed of a polishing module, rotation speed of a sample rotation module and polishing time, and polishing;

and S4, after polishing is finished, taking down the bearing ring, detecting the surface quality after polishing, and if the surface quality does not meet the requirement, carrying out S3 until the requirement is met.

Further, the chemical mechanical polishing solution comprises 0.01 to 40wt% of colloidal silica, 0 to 10wt% of hydrogen peroxide, and the balance of water, wherein the pH value is 2-11, the hydrogen peroxide is used as an oxidizing agent, a uniform and consistent reaction film can be generated on the surface of a sample, and the removal is realized under the action of the colloidal silica abrasive particles.

The contact type ultra-precise chemical mechanical polishing device and method for the bearing ring, provided by the invention, have the following beneficial effects:

1. the polishing heads and the clamps of the inner and outer rings are designed in a targeted manner, so that the ultra-precise polishing of the inner and outer rings of the bearing can be realized.

2. The polishing head, the bearing ring and the sample rotating module are highly coaxial through the first aligning module and the second aligning module, and on the basis, the rotating speeds of the sample rotating module and the polishing module and the homogenization errors are controlled, so that the surface of the bearing ring is uniformly polished.

3. The chemical mechanical polishing solution is designed for stainless bearing steel, hydrogen peroxide with a certain concentration is added as an oxidant, a uniform iron chromium oxide film is generated on the surface of the bearing steel, and the iron chromium oxide film is removed under the action of colloidal silica abrasive particles, so that the nano-scale surface roughness is realized.

Drawings

To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required in the embodiments will be briefly described below, and it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope.

FIG. 1 is a schematic overall view of a contact type ultra-precise chemical mechanical polishing apparatus for a bearing ring according to the present invention;

FIG. 2 is a schematic view of a sample rotation module and a housing of the present invention;

fig. 3 is a detail view of a first aligning module according to the present invention;

FIG. 4 is a detail view of a second centering module of the invention;

FIG. 5 is a detailed view of a sample clamping module for use in polishing an outer race of a bearing according to the present invention;

FIG. 6 is a detail view of a sample holding module for polishing a bearing inner race according to the present invention;

FIG. 7 is a detailed view of a polishing module for polishing an outer race of a bearing according to the present invention;

FIG. 8 is a detailed view of a polishing module for polishing an inner race of a bearing according to the present invention;

FIG. 9 is a schematic view of an outer race of a polished bearing of the present invention;

FIG. 10 is a schematic view showing the structure of an inner race of a polished bearing according to the present invention and a detailed comparison;

FIG. 11 is a comparison of test results of the bearing inner race of the present invention before and after polishing, wherein the left is before polishing and the right is after polishing;

FIG. 12 is a graph showing the results of a three-dimensional shape measurement test performed after polishing the inner ring of the bearing according to the present invention, wherein the left graph is a large diameter portion of the inner ring of the bearing, and the right graph is a small diameter portion of the inner ring of the bearing;

FIG. 13 is a comparison of test results of the bearing outer race of the present invention before and after polishing, wherein the left side is before polishing and the right side is after polishing;

description of the drawings: 1-a first aligning module; 2-a second aligning module; 3-a sample rotation module; 4-a sample holding module; 5-polishing the module; 6-a machine base; 101-a motor frame; 102-a first support bar; 103-a second support bar; 104-open fixed ring; 105-a first connection plate; 106-a second connection plate; 201-two-dimensional workbench; 202-upper positioning holes; 203-lower positioning holes; 204-a first direction knob; 205-a second direction knob; 301-a rotating disk; 302-rotating disk switch; 303-rotating the disc speed regulating knob; 401-bearing outer race clamp; 402-a polishing liquid pool; 403-cushion block; 404-bearing outer race; 405-short pins; 406-long pins; 407-bearing inner race clamp; 408-bearing inner race; 501-a motor; 502-a motor controller; 503-polishing head of bearing outer ring; 504-a polishing pad; 505-bearing inner race polishing head.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

Referring to fig. 1 to 10, the present embodiment provides a contact type ultra-precise chemical mechanical polishing apparatus for a bearing ring, which includes a first aligning module 1, a second aligning module 2, a sample rotating module 3, a sample clamping module 4, a polishing module 5, and a machine base 6; the polishing object bearing ring comprises a bearing outer ring 404 and a bearing inner ring 408; the sample rotating module 3 and the first aligning module 1 are respectively arranged on the base 6, the polishing module 5 is arranged on the first aligning module 1, the second aligning module 2 is arranged on the sample rotating module 3, the sample clamping module 4 is arranged on the second aligning module 2, the first aligning module 1 comprises a motor frame 101, a first supporting rod 102, a second supporting rod 103 and an opening fixing ring 104, the second aligning module 2 comprises a two-dimensional workbench 201, an upper positioning hole 202, a lower positioning hole 203, a first direction knob 204 and a second direction knob 205, the sample rotating module 3 comprises a rotating disc 301, a rotating disc switch 302 and a rotating disc speed regulating knob 303, the sample clamping module 4 comprises a bearing outer ferrule clamp 401, a bearing ferrule inner ferrule clamp 407, a polishing liquid pool 402 and a polishing head cushion block 403, and the polishing module 5 comprises a bearing outer ferrule clamp 503, a bearing inner ferrule 505, a motor 501 and a motor controller 502.

Referring to fig. 3, the first aligning module 1 mainly functions to adjust the positions of the motor frame 101 in the horizontal direction and the vertical direction, and drive the polishing module 5, so that the polishing head and the bearing ring are coaxial; the bottoms of the three second support rods 103 are provided with cylindrical holes, cylindrical rods of the engine base 6 are inserted into the cylindrical holes, the three first support rods 102 are located on the three matched second support rods 103 through bolt fixing connection on the side face, three first connecting plates 105 are arranged at the ends, away from the motor frame 101, of the three first support rods 102, three second connecting plates 106 connected with the three first connecting plates 105 are arranged at the ends, away from the engine base 6, of the three second support rods 103, hole grooves are formed in the first connecting plates 105 and the second connecting plates 106, the first connecting plates 105 move relative to the second connecting plates 106 along the hole grooves, so that the first support rods 102 move relative to the second support rods 103 in the horizontal direction, the motor frame 101 is fixed through bolt connection after the position is adjusted, the motor frame 101 is located on the first support rods 102 and can move in the vertical direction along the first support rods 102, after the position is adjusted, the three opening fixing rings 104 on the motor frame 101 are used for fixing the position of the motor frame 101 in the vertical direction, and the motor frame 101 is ensured to be horizontal.

Referring to fig. 2 and 4, the second aligning module 2 mainly functions to adjust the horizontal position of the sample holding module 4 on the table top through the two-dimensional worktable 201, so that the bearing ring is coaxial with the sample rotating module 3. The two-dimensional workbench 201 is controlled by rotating a first direction knob 204 and a second direction knob 205 to move towards a first direction and a second direction, the two directions are perpendicular to each other, scales are marked on the two knobs, the position of the sample clamping module 4 can be determined, a plurality of upper positioning holes 202 are formed in the table surface of the two-dimensional workbench 201 and used for fixing the sample clamping module 4, four lower positioning holes 203 are formed below the two-dimensional workbench 201 and used for fixing the two-dimensional workbench 201 on a rotating disc 301 of the sample rotating module 3 through screws, the two-dimensional workbench 201 rotates along with the sample rotating module 3, so that a bearing ring on the sample clamping module 4 is driven to rotate, the rotating disc 301 is stopped or rotated through a rotating disc switch 302, different rotating speeds of the rotating disc 301 are realized through a rotating disc speed regulating knob 303, lower rotating speeds are set, the problem of uneven stress on the surface of the bearing ring caused by polishing head processing errors is solved, errors are homogenized, and high surface type precision of the bearing ring is ensured.

Referring to fig. 5 and 6, the main function of the sample holding module 4 is to provide the inner and outer ring clamps of the bearing with pertinence, and to contain the polishing solution; the bearing ring clamp comprises a bearing outer ring clamp 401 and a bearing inner ring clamp 407 which are respectively used for fixing a bearing outer ring 404 and a bearing inner ring 408, a polishing solution pool 402 is used for containing polishing solution and fixing the bearing ring clamp, the polishing solution pool 402 is fixed on a cushion block 403, the cushion block 403 is fixed on a second aligning module 2 through two short pins 405 and two long pins 406 and moves and rotates along with the second aligning module 2, after polishing is finished, after a positioning pin is taken down, the cushion block 403 is taken out, the sample clamping module 4 is moved downwards, the bearing ring is separated from the polishing head, and the bearing ring is taken out.

The bottom of the bearing outer ring clamp 401 is a disc base with the outer diameter the same as the inner diameter of the polishing liquid pool 402, a cylinder coaxial with the disc base is arranged above the disc base, a stepped hole coaxial with the cylinder is formed in the cylinder, the diameter of the upper portion of the stepped hole is slightly larger than the outer diameter of the bearing outer ring 404, the bearing outer ring 404 can be conveniently placed in the cylindrical base, four threaded holes are formed in the upper portion of the stepped hole, the bearing outer ring 404 is screwed down through screws to be prevented from rotating, the inner diameter of the lower portion of the stepped hole is smaller than the outer diameter of the bearing outer ring 404 and larger than the inner diameter of the bearing outer ring 404, the bearing outer ring 404 is kept at a specific height, meanwhile, the whole inner surface of the bearing outer ring 404 can be conveniently polished, four notches are uniformly formed in the periphery of the cylinder, and polishing liquid can conveniently enter the cylindrical base; the bottom of the bearing inner ring clamp 407 is a disc base with the outer diameter being the same as the inner diameter of the polishing solution pool 402, a stepped shaft coaxial with the disc base is arranged above the disc base, the diameter of the upper portion of the stepped shaft is the same as the inner diameter of the bearing inner ring 408, the bearing inner ring 408 is mounted on the upper portion of the stepped shaft through interference fit, the diameter of the lower portion of the stepped shaft is larger than the inner diameter of the bearing inner ring 408 and smaller than the outer diameter of the bearing inner ring 408, the bearing inner ring 408 is kept at a specific height, and meanwhile the polishing head is convenient to polish the whole outer surface of the bearing inner ring 408.

Referring to fig. 7 and 8, the polishing module 5 mainly functions to provide polishing heads for the inner and outer races of the bearing in a targeted manner, and control the polishing heads to rotate so as to polish the bearing races; the polishing head is composed of a substrate and a polishing pad 504, the polishing pad 504 is adhered to the surface of the substrate, the substrate and the polishing pad 504 are made of flexible materials, elasticity and matching are comprehensively considered, the substrate is made of 70-degree silica gel, and the polishing pad 504 is made of porous polyurethane.

The substrate of the bearing outer race polishing head 503 is a cylinder, the upper part of the bearing outer race polishing head is provided with a cylindrical hole with the inner diameter same as the outer diameter of the motor shaft, and the cylindrical hole is provided with a key groove, and after the polishing pad 504 is adhered to the outer surface of the cylinder, the outer diameter of the cylindrical hole is the same as the inner diameter of the bearing outer race 404; the substrate of the polishing head 505 of the bearing inner ring is a cylinder, the upper part of the polishing head is provided with a cylindrical hole with the inner diameter being the same as the outer diameter of the motor shaft and a key groove, the lower part of the polishing head is provided with a cylindrical hole, and the inner diameter of the cylindrical hole is the same as the outer diameter of the bearing inner ring 408 after the polishing pad 504 is adhered to the inner surface of the cylindrical hole.

Motor 501 fixes in the center of motor frame 101, and the burnishing head passes through the key-type connection on motor 501's axle, and through control motor controller 502, motor 501 can realize different rotational speeds to it is rotatory to drive the burnishing head, sets up higher rotational speed, under the combined action of polishing pad 504 and chemical mechanical polishing liquid, polishes the bearing ring.

Referring to fig. 9 and 10, a contact ultra-precise chemical mechanical polishing apparatus for a bearing ring according to a first embodiment of the present invention is used for polishing, and the polishing method includes the following steps:

s1, fixedly installing a second aligning module 2 on a sample rotating module 3, installing a bearing ring on a sample clamping module 4, fixedly installing the sample clamping module 4 on the second aligning module 2, sequentially installing a first aligning module 1 and a polishing module 5, adjusting positions through the first aligning module 1 and the second aligning module 2 to enable a polishing head, the bearing ring and the sample rotating module 3 to be coaxial, and meanwhile ensuring that the polishing head is fully contacted with the bearing ring;

s2, preparing a chemical mechanical polishing solution, wherein the bearing ring is made of 9Cr18Mo stainless bearing steel, the polishing solution comprises 2 wt% of colloidal silica, 1 wt% of hydrogen peroxide and the balance of water, the pH value is 4, the polishing solution is uniformly stirred and poured into a polishing solution pool 402, wherein the 2 wt% of colloidal silica can provide sufficient mechanical action, the 1 wt% of hydrogen peroxide can generate a uniform iron-chromium oxide film on the surface of the bearing steel, the passivation effect is realized, the nanoscale surface roughness is facilitated to be realized, and the material removal rate and the surface roughness can be considered at the pH value of 4;

s3, setting polishing process parameters, wherein the environment temperature is set to be 22-23 ℃, the rotating speed of the polishing module 5 is set to be 280 r/min, the rotating speed can realize high-speed polishing and can also ensure that polishing liquid cannot splash out of a polishing liquid pool 402, the rotating speed of the sample rotating module 3 is set to be 10 r/min, the rotating speed can reduce the problem of uneven stress on the surface of a bearing ring caused by the processing error of a polishing head and the homogenization error, and the polishing is carried out after the parameters are set;

and S4, after polishing is finished, taking down the bearing ring, and detecting the surface quality of the polished bearing ring by using a three-dimensional appearance.

The photos of the bearing ring before and after polishing are shown in fig. 11 and fig. 13, and the comparison shows that the surfaces of the inner ring and the outer ring of the bearing before and after polishing can only reflect the fuzzy reflection, the clear reflection can be reflected after the polishing, and the surface quality is obviously improved. The detection result of the polished three-dimensional topographer is shown in FIG. 12, wherein the left graph is the surface roughness of the large diameter part of the bearing inner ring 408S _a 1.02 nm, and the right graph shows the surface roughness of the small diameter part of the inner ring 408 of the bearingS _a Is 1.32 nm.

In conclusion, the invention discloses a contact type ultra-precise chemical mechanical polishing device and a contact type ultra-precise chemical mechanical polishing method for a bearing ring, and the polishing heads and the clamps of the inner and outer bearing rings are designed in a targeted manner; controlling the rotating speed of the sample rotating module and the polishing module, homogenizing errors and realizing uniform polishing of the surface of the bearing ring; the polishing solution is designed aiming at stainless bearing steel, so that the surface roughness of the bearing ring is close to 1 nm, and compared with the test result of the ultraprecise flexible chemical mechanical polishing device and method for the miniature bearing core element in the invention patent, the surface roughness is reduced by one order of magnitude, and the ultraprecise processing of the bearing ring is realized.

This description describes examples of embodiments of the invention, and is not intended to illustrate and describe all possible forms of the invention. It will be appreciated by those of ordinary skill in the art that the embodiments described herein are intended to assist the reader in understanding the principles of the invention and are to be construed as being without limitation to such specifically recited embodiments and examples. Those skilled in the art, having the benefit of this disclosure, may effect numerous modifications thereto and changes may be made without departing from the scope of the invention in its aspects.

Claims

1. The utility model provides a bearing ring contact ultra-precision chemical mechanical polishing device which characterized in that: the device comprises a first aligning module, a second aligning module, a sample rotating module, a sample clamping module, a polishing module and a base; the base is respectively provided with the sample rotating module and the first aligning module, the first aligning module is provided with the polishing module, the sample rotating module is provided with the second aligning module, the second aligning module is provided with the sample clamping module, the second aligning module is used for driving the sample clamping module to move in the horizontal direction, so that the bearing ring on the sample clamping module is coaxial with the sample rotating module, the first aligning module is used for driving the polishing module to move in the horizontal direction and the vertical direction, so that the polishing head of the polishing module is coaxial with the bearing ring, the sample rotating module is used for driving the second aligning module to rotate, the sample clamping module rotates along with the second aligning module, so that the bearing ring is driven to rotate, the sample clamping module is used for clamping the bearing ring by a targeted clamp, and the polishing module is used for polishing the bearing ring by a targeted clamp;

the first aligning module comprises a motor frame, a first supporting rod, a second supporting rod and an opening fixing ring; the motor frame is characterized in that a cylindrical hole is formed in the bottom of the second supporting rod, a cylindrical rod of the motor frame is inserted into the cylindrical hole, the cylindrical rod is fixedly connected through a bolt, the first supporting rod is located on the second supporting rod, a first connecting plate is arranged at one end, away from the motor frame, of the first supporting rod, a second connecting plate in matched connection with the first connecting plate is arranged at one end, away from the motor frame, of the second supporting rod, a hole groove is formed in the first connecting plate and the second connecting plate, the first connecting plate moves relative to the second connecting plate along the hole groove, the first supporting rod moves relative to the second supporting rod in the horizontal direction, the motor frame is fixedly connected through the bolt after the position is adjusted, the motor frame is located on the first supporting rod, the motor frame moves relative to the first supporting rod in the vertical direction, and after the position is adjusted, the opening fixing ring arranged on the motor frame is used for fixing the motor frame.

2. The contact ultra-precise chemical mechanical polishing device for a bearing ring according to claim 1, wherein the second aligning module comprises: the device comprises a two-dimensional workbench, an upper positioning hole, a lower positioning hole, a first direction knob with scales and a second direction knob; the two-dimensional workbench is characterized in that the two first direction knobs with scales and the two second direction knobs are rotated to control the console to move towards the first direction and the second direction, the two directions are perpendicular to each other, a plurality of upper positioning holes are arranged above the table top of the two-dimensional workbench and used for fixing the sample clamping module, and four lower positioning holes are arranged below the two-dimensional workbench and used for fixing the two-dimensional workbench on the sample rotating module through screws so that the two-dimensional workbench rotates along with the sample rotating module.

3. The contact ultra-precision chemical mechanical polishing device for a bearing ring according to claim 1, wherein the sample holding module comprises: the device comprises a bearing ring clamp, a polishing solution pool and a cushion block; the bearing ring clamp is fixed in the polishing liquid pool, the polishing liquid pool is fixed in a circular groove on the cushion block, the inner diameter of the circular groove is the same as the outer diameter of the polishing liquid pool, on the basis, the polishing liquid pool and the cushion block are fixedly connected through pins to limit the polishing liquid pool to rotate relative to the cushion block, the cushion block is fixedly connected on the second aligning module through pins and follows the second aligning module to move and rotate, the cushion block is taken out after polishing is finished, the sample clamping module moves downwards, the bearing ring is separated from the polishing head, and the bearing ring is taken out.

4. The contact ultra-precision chemical mechanical polishing device for a bearing ring according to claim 3, wherein the bearing ring holder comprises: a bearing outer ring clamp and a bearing inner ring clamp; the bottom of the bearing outer ring clamp is provided with a disc base with the outer diameter the same as the inner diameter of the polishing solution pool, a cylinder coaxial with the disc base is arranged above the disc base, a stepped hole coaxial with the cylinder is formed in the cylinder, the inner diameter of the upper part of the stepped hole is slightly larger than the outer diameter of the bearing outer ring, the bearing outer ring is conveniently placed in the cylinder, the upper part of the stepped hole is provided with four threaded holes, the bearing outer ring is fixed through screwing down of screws and is prevented from rotating, the inner diameter of the lower part of the stepped hole is smaller than the outer diameter of the bearing outer ring and larger than the inner diameter of the bearing outer ring, and four notches are uniformly formed around the cylinder, so that polishing solution can conveniently enter the cylinder; the polishing liquid pool is characterized in that a disc base with the outer diameter being the same as the inner diameter of the polishing liquid pool is arranged at the bottom of the bearing inner ring clamp, a stepped shaft coaxial with the disc base is arranged above the disc base, the diameter of the upper portion of the stepped shaft is the same as the inner diameter of the bearing inner ring, the bearing inner ring is arranged on the upper portion of the stepped shaft in an interference fit mode, and the diameter of the lower portion of the stepped shaft is larger than the inner diameter of the bearing inner ring and smaller than the outer diameter of the bearing inner ring.

5. The contact type ultra-precise chemical mechanical polishing device for the bearing ring according to claim 1, wherein the polishing module comprises: a motor, a controller and a polishing head; the motor is fixed at the center of the motor frame, the polishing head is connected to a motor shaft through a key, the motor reaches a set rotating speed by adjusting the controller, the polishing head is driven to rotate, and the polishing head and the bearing ring generate relative motion, so that a polishing effect is achieved.

6. The contact type ultra-precise chemical mechanical polishing device for the bearing ring according to claim 5, wherein the polishing head comprises a substrate and a polishing pad, the polishing pad is adhered to the surface of the substrate, the substrate and the polishing pad are both made of flexible materials, the substrate is made of silica gel, rubber or silicon rubber, and the polishing pad is made of polyurethane, wool, cow leather or nylon.

7. The contact ultra-precise chemical mechanical polishing device for a bearing ring according to claim 5, wherein the polishing head comprises: a bearing outer ring polishing head and a bearing inner ring polishing head; the substrate of the polishing head of the bearing outer ring is a cylinder, the upper part of the polishing head is provided with a cylinder hole with the inner diameter being the same as the outer diameter of the motor shaft, the polishing head is additionally provided with a key groove, and the outer diameter of the cylinder is the same as the inner diameter of the bearing outer ring after a polishing pad is adhered to the outer surface of the cylinder; the bearing inner ring polishing head is characterized in that a substrate of the bearing inner ring polishing head is a cylinder, the upper portion of the bearing inner ring polishing head is provided with a cylindrical hole with the inner diameter being the same as the outer diameter of a motor shaft and a key groove, the lower portion of the bearing inner ring polishing head is provided with a cylindrical hole, and after a polishing pad is adhered to the inner surface of the cylindrical hole, the inner diameter is the same as the outer diameter of the bearing inner ring.

8. A contact type ultra-precise chemical mechanical polishing method for a bearing ring, which is characterized in that a contact type ultra-precise chemical mechanical polishing device for a bearing ring according to any one of the claims 1 to 7 is adopted, and comprises the following steps:

s1, fixedly mounting a second aligning module on a sample rotating module, mounting a bearing ring on a sample clamping module, fixedly mounting the sample clamping module on the second aligning module, sequentially mounting a first aligning module and a polishing module, and respectively adjusting the positions of a polishing head and the bearing ring through the first aligning module and the second aligning module to enable the polishing head, the bearing ring and the sample rotating module to be coaxial;

s2, preparing a chemical mechanical polishing solution, uniformly stirring, and pouring into a polishing solution pool;

s3, setting polishing process parameters including environment temperature, rotation speed of the polishing module, rotation speed of the sample rotation module and polishing time, and polishing;

and S4, after polishing is finished, taking down the bearing ring, detecting the surface quality after polishing, and if the surface quality does not meet the requirement, repeating S3 until the requirement is met.

9. A method of contact ultra-precise chemical mechanical polishing of a bearing ring according to claim 8, characterized in that: the chemical mechanical polishing solution comprises 0.01 to 40wt% of colloidal silicon dioxide, 0 to 10wt% of hydrogen peroxide and the balance of water, and the pH value is 2-11.