CN114700870B - Contact type ultra-precision chemical mechanical polishing device and method for bearing ring - Google Patents

Abstract

The invention discloses a bearing ring contact type ultra-precision chemical mechanical polishing device and method. The polishing device includes a first centering module, a second centering module, a sample rotation module, a sample clamping module, a polishing module and a machine base; The second centering module adjusts the position of the sample holding module, drives the ferrule on the sample holding module, and makes the ferrule coaxial with the sample rotating module, the first centering module adjusts the position of the polishing module, drives the polishing head on the polishing module, Make the polishing head coaxial with the ferrule. The polishing head rotates at high speed for polishing, and the sample rotates at low speed to homogenize the error, and cooperate to realize ultra-precision polishing of the ferrule. The chemical mechanical polishing liquid includes 0.01-40wt% of colloidal silicon dioxide, 0-10wt% of hydrogen peroxide, the rest is water, and the pH value is 2-11. The invention specifically designs inner and outer ring polishing heads and fixtures; controls the rotational speed of the sample rotation module and the polishing module, averages errors, and realizes uniform polishing on the surface of the ring; designs a polishing liquid for stainless bearing steel to achieve nano-level surface roughness.

Description

A bearing ring contact type ultra-precision chemical mechanical polishing device and method

technical field

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

Background technique

Bearings are very important parts in mechanical equipment, and their main function is to support the rotating mechanism, reduce the friction coefficient, and ensure the rotation accuracy. With the rapid development of science and technology, bearings are gradually used in high-end equipment in aerospace, machinery manufacturing, rail transit and other fields. Under working conditions, harsh lubricating conditions such as a sharp decrease in the lubricating film thickness are likely to occur. If the bearing surface roughness is large at this time, the lubricating film thickness is smaller than the height of the roughness peaks, and the roughness peaks will be in direct contact, and the bearing surface will be worn , affecting the service performance and life of the bearing. To this end, it is necessary to make continuous breakthroughs in materials, design, manufacturing, testing, etc. to ensure the excellent service performance of bearings and meet the technical needs of high-end equipment.

From the perspective of bearing manufacturing, it is necessary to develop new ultra-precision machining technology, improve machining accuracy, reduce surface roughness, increase film thickness ratio (ratio of lubricating oil film thickness to surface roughness), and avoid direct contact between rough peaks on the surface of friction pairs , to achieve a good lubrication state, thereby improving the service performance and life of the bearing, and ultimately ensuring the stable and reliable operation of the equipment. According to reference (Hiroki Komata, Yasuhiro Iwanaga, Tohru Ueda, Koji Ueda, Nobuaki Mitamura, Enhanced Performance of Rolling Bearings by Improving the Resistance of Rolling Elements to Surface Degradation, in: J.M. Beswick (Ed.) Bearing Steel Technologies: 10th Volume, Advances Steel Technologies for Rolling Bearings, ASTM International, West Conshohocken, PA, 2015, pp. 272-290), when the surface roughness of the raceway of the outer ring of the bearing is 30 nm, and the surface roughness of the raceway of the inner ring is 50 nm, the ball The surface roughness was reduced from 209 nm to 6 nm, and the flaking life of the bearing was increased by about 5 times. It can be inferred that bearing rings and rolling elements are a pair of friction pairs, and reducing the surface roughness of either or both is beneficial to improve the service performance and life of the bearing.

At present, oilstone honing is usually used as the final finishing method for bearing rings, and the surface roughness can be reduced to below 100 nm at this time. In order to further improve the machining accuracy of bearings and reduce surface roughness, some new ultra-precision machining methods have been proposed in the industry, such as electrochemical grinding, magnetorheological polishing, and force rheological polishing. There are deficiencies as follows:

1) Both magnetorheological polishing and force rheological polishing use purely mechanical scribing to remove bearing surface materials. When removing, the contact pressure needs to reach the plastic yield limit of the material, the minimum removal thickness is limited, and the surface quality of the bearing is difficult to further improve;

2) Mechano-rheological polishing mainly achieves the thickening effect of the polishing liquid by increasing the shear rate. However, for the curved surface, the relative speed of each position is not the same, and there are many factors that affect the processing uniformity of the curved surface. It is more difficult to control, and it is more difficult to improve the accuracy of surface shape.

The concept of chemical mechanical polishing was first proposed by Monsanto in 1965, and then the International Business Machines Corporation of the United States continued to improve the chemical mechanical polishing process. After decades of development, it has been widely used in the manufacture of VLSI. Chemical mechanical polishing can achieve sub-nanometer surface roughness and nanometer surface precision, as well as close to zero surface defects and close to zero deterioration on the plane of the silicon wafer through the synergistic effect of chemical reaction and mechanical force layer thickness. In view of the technical advantages of chemical mechanical polishing, it is organically combined with traditional ultra-precision machining methods to develop some new ultra-precision machining methods and apply them to bearing ultra-precision machining.

A Chinese invention patent "ultra-precision flexible chemical mechanical polishing device and method for core components of miniature bearings" (patent number: ZL202010118552.8, date of authorization: February 26, 2021) has been authorized by our research group, which discloses a The ultra-precision flexible chemical-mechanical polishing device and method for the core component of the miniature bearing can realize ultra-precision machining of the surface of the core component and conformal processing of complex curved surfaces by optimizing the synergistic effect of chemical reaction and mechano-rheological effect and mechanical force. However, in the actual application process, this method has the following shortcomings:

1) The flexible chemical mechanical polishing fluid of this method uses polyhydroxyl polymers as non-Newtonian fluids for shear thickening. Polyhydroxyl polymers may react with other chemical reagents in the polishing fluid and affect the polishing effect;

2) As mentioned above, this method mainly achieves shear thickening polishing by impacting the surface of the core component of the bearing with the polishing liquid at high speed. However, for core components such as bearing rings and rolling elements, the machining uniformity of the component surface is affected. There are many factors that are difficult to control, and it is difficult to improve the accuracy of surface shape.

As mentioned above, designing a device and method for ultra-precision polishing of bearing rings and solving various problems existing in the existing ultra-precision machining is of great significance for guiding the ultra-precision machining of bearing rings.

Contents of the invention

In order to overcome the deficiencies of the above-mentioned prior art, the present invention provides a bearing ring contact type ultra-precision chemical mechanical polishing device and method, including the following content:

A contact type ultra-precision chemical mechanical polishing device for a bearing ring, comprising: a first aligning module, a second aligning module, a sample rotating module, a sample holding module, a polishing module and a base; the base is respectively provided with samples The rotating module and the first centering module, the first centering module is provided with a polishing module, the sample rotating module is provided with a second centering module, the second centering module is provided with a sample holding module, and the second centering module It is used to drive the sample holding module to move in the horizontal direction, so that the bearing ring on the sample holding module is coaxial with the sample rotating module, and the first self-aligning module is used to drive the polishing module to move in the horizontal and vertical directions , so that the polishing head on the polishing module is coaxial with the bearing ring, the sample rotation module is used to drive the second self-aligning module to rotate, the sample holding module rotates with the second self-aligning module, thereby driving the bearing ring to rotate, and the sample holder The holding module provides fixtures for clamping the bearing rings, and the polishing module provides polishing heads for polishing the bearing rings.

Further, the first centering module includes a motor frame, a first support rod, a second support rod and an open fixed ring; a cylindrical hole is provided at the bottom of the second support rod, and a cylindrical rod that comes with the machine base is inserted into the cylindrical hole, and the bolt Fixed connection, the first support rod is located on the second support rod, the end of the first support rod away from the motor frame is provided with a first connecting plate, and the end of the second support rod away from the machine base is provided with a second connecting plate matched with the first connecting plate. Two connecting plates, the first connecting plate and the second connecting plate are provided with holes, the first connecting plate moves relative to the second connecting plate along the hole, so that the first support rod moves in the horizontal direction relative to the second support rod, After adjusting the position, connect and fix it with bolts. The motor frame is located on the first support rod and can move vertically along the first support rod. After adjusting the position, the open fixing ring set on the motor frame is used to fix the motor frame. position, make sure the motor frame is level.

Further, the second centering module includes: a two-dimensional workbench, an upper positioning hole, a lower positioning hole, a scaled first direction knob and a second direction knob; the two-dimensional workbench rotates two scaled first direction and The second direction knob console moves in the first direction and the second direction, and the two directions are perpendicular to each other. The scale on the knob can determine the position of the sample holding module. There are multiple upper positioning holes on the two-dimensional workbench for Fix the sample clamping module, there are four lower positioning holes under the two-dimensional worktable, which are used to fix the two-dimensional workbench on the sample rotation module with screws, so that the two-dimensional workbench rotates with the sample rotation module and drives the sample holder Hold the module to rotate, set a lower speed, reduce the problem of uneven force on the surface of the bearing ring caused by the processing error of the polishing head, homogenize the error, and ensure the high surface accuracy of the bearing ring.

Further, the sample holding module includes: a bearing ring fixture, a polishing liquid pool and a pad; the polishing liquid pool is used to accommodate the polishing liquid and fix the bearing ring fixture, and the polishing liquid pool is fixed on the circular groove on the pad Inside, the inner diameter of the circular groove is the same as the outer diameter of the polishing liquid pool. On this basis, the polishing liquid pool and the pad are fixedly connected by pins, which limits the rotation of the liquid pool relative to the pad, and the pad is fixedly connected by pins. On the second centering module, follow the second centering module to move and rotate. After polishing, remove the positioning pin, take out the spacer, move the sample holding module down, separate the bearing ring from the polishing head, and take out the bearing sleeve lock up.

Further, the bearing ring clamp includes: a bearing outer ring clamp, a bearing inner ring clamp; the bottom of the bearing outer ring clamp is a disc base with the same outer diameter as the inner diameter of the polishing liquid pool, and the top of the disc base is a The shaft is a cylinder, and there is a coaxial stepped hole inside 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, which is convenient for the bearing outer ring to be inserted. There are four threaded holes in the upper part of the stepped hole, and the bearing outer is fixed by screwing. ring, to prevent it 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, and at the same time it is convenient for the bearing outer ring polishing head to polish the entire inner surface of the bearing outer ring, around the cylinder Four gaps are evenly set to facilitate the entry of polishing liquid; the bottom of the bearing inner ring fixture is a disc base with the same outer diameter as the inner diameter of the polishing liquid pool, and a stepped shaft coaxial with it is above the disc base, and the upper part of the stepped shaft is The diameter is the same as the inner diameter of the inner ring of the bearing. The inner ring of the bearing is installed on the upper part of the stepped shaft through interference fit. The diameter of the lower part of the stepped shaft is larger than the inner diameter of the inner ring of the bearing and smaller than the outer diameter of the inner ring of the bearing. At the same time, it is convenient for the polishing head to polish the entire outer surface of the inner ring of the bearing.

Further, the polishing module includes: a polishing head, a motor, and a motor controller; the polishing head is composed of a substrate and a polishing pad, and the polishing pad is adhered to the surface of the substrate. Both the substrate and the polishing pad are made of flexible materials, and the substrate material is Silicone, rubber or silicone rubber, polishing pad material is polyurethane, wool, cowhide or nylon.

Further, the polishing head includes: a polishing head for the outer bearing ring, a polishing head for the inner ring of the bearing; the substrate of the polishing head for the outer bearing ring is a cylinder, and the upper part has a cylindrical hole with the same inner diameter as the outer diameter of the motor shaft, and a keyway, cylindrical After the polishing pad is adhered to the outer surface, the outer diameter is the same as the inner diameter of the bearing outer ring; the substrate of the bearing inner ring polishing head is a cylinder, the upper part has a cylindrical hole with the same inner diameter as the motor shaft outer diameter, and a keyway, and the lower part has a Cylindrical hole, after the inner surface of the cylindrical hole adheres the polishing pad, the inner diameter is the same as the outer diameter of the inner ring of the bearing.

Further, the motor is fixed at the center of the motor frame, and the polishing head is connected to the motor shaft through a key. By adjusting the motor controller, the motor can reach different speeds to drive the polishing head to rotate, and a higher speed is set. Under the combined action of the fluid, the bearing ring is polished.

Further, a bearing ring contact type ultra-precision chemical mechanical polishing device provided by the present invention is used for polishing, and the polishing method includes the following steps:

S1. Fix the second alignment module on the sample rotation module, install the bearing ring on the sample holding module, fix the sample holding module on the second alignment module, and install the first alignment module in sequence 1. The polishing module, adjusting the positions of the polishing head and the bearing ring respectively through the first centering module and the second centering module, so that the polishing head, the bearing ring and the sample rotation module are coaxial;

S2, configure the chemical mechanical polishing liquid, stir evenly, and pour it into the polishing liquid liquid pool;

S3. Set the polishing process parameters, including the ambient temperature, the rotational speed of the polishing module, the rotational speed of the sample rotation module, and the polishing time, and perform polishing;

S4. After polishing, remove the bearing ring and check the surface quality after polishing. If the requirements are not met, proceed to S3 until the requirements are met.

Further, the chemical mechanical polishing solution includes 0.01-40 wt% colloidal silicon dioxide, 0-10 wt% hydrogen peroxide, and the rest is water, with a pH value of 2-11, wherein hydrogen peroxide is used as an oxidizing agent and can be used in samples A uniform and consistent reaction film is formed on the surface, and the removal is achieved under the action of colloidal silica abrasive particles.

A bearing ring contact type ultra-precision chemical mechanical polishing device and method provided by the present invention have the following beneficial effects:

1. Targeted design of inner and outer ring polishing heads and fixtures can realize ultra-precision polishing of bearing inner and outer rings.

2. Through the first and second centering modules, the polishing head, the bearing ring and the sample rotation module are highly coaxial. On this basis, the speed of the sample rotation module and the polishing module is controlled, and the error is averaged to realize the bearing ring. The surface is evenly polished.

3. Design a chemical mechanical polishing solution for stainless bearing steel, add a certain concentration of hydrogen peroxide as an oxidant, and form a uniform iron-chromium oxide film on the surface of the bearing steel, and remove it under the action of colloidal silica abrasive particles , to achieve nanoscale surface roughness.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and thus should be seen as limiting the scope.

Fig. 1 is an overall schematic diagram of a bearing ring contact type ultra-precision chemical mechanical polishing device of the present invention;

Fig. 2 is the schematic diagram of sample rotation module and machine base of the present invention;

Fig. 3 is a detailed view of the first aligning module of the present invention;

Fig. 4 is the detailed diagram of the second centering module of the present invention;

Fig. 5 is a detailed view of the sample holding module used for polishing the bearing outer ring of the present invention;

Fig. 6 is a detailed view of the sample holding module used for polishing the bearing inner ring of the present invention;

Fig. 7 is a detailed view of the polishing module used for polishing the bearing outer ring of the present invention;

Fig. 8 is a detailed view of the polishing module used for polishing the bearing inner ring of the present invention;

Fig. 9 is a schematic diagram of the polished bearing outer ring of the present invention;

Fig. 10 is a structural schematic diagram and detailed comparison diagram of the polished bearing inner ring of the present invention;

Fig. 11 is a comparison diagram of test results before and after polishing of the bearing inner ring of the present invention, wherein the left picture is before polishing, and the right picture is after polishing;

Fig. 12 is a three-dimensional shape measurement test result diagram of the inner ring of the bearing after polishing in the present invention, wherein the left picture is the large diameter of the inner ring of the bearing, and the right picture is the small diameter of the inner ring of the bearing;

Fig. 13 is a comparison diagram of test results before and after polishing of the bearing outer ring of the present invention, wherein the left picture is before polishing, and the right picture is after polishing;

Description of drawings: 1-the first alignment module; 2-the second alignment module; 3-sample rotation module; 4-sample clamping module; 5-polishing module; 103-second support rod; 104-opening fixing ring; 105-first connecting plate; 106-second connecting plate; 201-two-dimensional workbench; 202-upper positioning hole; 203-lower positioning hole ;204-first direction knob; 205-second direction knob; 301-rotary disc; 302-rotary disc switch; 303-rotary disc speed control knob; 401-bearing outer ring fixture; ;403-pad; 404-bearing outer ring; 405-short pin; 406-long pin; 407-bearing inner ring fixture; 408-bearing inner ring; 501-motor; 502-motor controller; 503-bearing Outer ring polishing head; 504-polishing pad; 505-bearing inner ring polishing head.

Detailed ways

In order to make the purpose, 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 in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. The components of the embodiments of the invention generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations.

Accordingly, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Please refer to Fig. 1 to Fig. 10, this embodiment provides a bearing ring contact type ultra-precision chemical mechanical polishing device, the device includes a first alignment module 1, a second alignment module 2, a sample rotation module 3, a sample holder holding module 4, polishing module 5 and machine base 6; the bearing ring to be polished includes bearing outer ring 404 and bearing inner ring 408; The centering module 1 is provided with a polishing module 5, the sample rotating module 3 is provided with a second centering module 2, the second centering module 2 is provided with a sample holding module 4, and the first centering module 1 includes a motor frame 101 , the first support rod 102, the second support rod 103, the open fixed ring 104, the second alignment module 2 includes 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 rotation module 3 includes a rotary disc 301, a rotary disc switch 302 and a rotary disc speed control knob 303, and the sample clamping module 4 includes a bearing outer ring clamp 401, a bearing inner ring clamp 407, and a polishing liquid pool 402 and pad 403, the polishing module 5 includes a bearing outer ring polishing head 503, a bearing inner ring polishing head 505, a motor 501 and a motor controller 502.

Please refer to Fig. 3, the main function of the first centering module 1 is to adjust the position of the motor frame 101 in the horizontal direction and the vertical direction, and drive the polishing module 5, so that the polishing head is coaxial with the bearing ring; The bottom of the rod 103 is provided with a cylindrical hole, which is inserted into the cylindrical rod of the machine base 6 and fixedly connected by the bolts on the side. The three first support rods 102 are located on the matched three second support rods 103, and the three first support rods One end of the rod 102 away from the motor frame 101 is provided with three first connecting plates 105, and one end of the three second support rods 103 away from the base 6 is provided with three second connecting plates 106 matched with the three first connecting plates 105, Grooves are arranged on the first connecting plate 105 and the second connecting plate 106, and the first connecting plate 105 moves relative to the second connecting plate 106 along the hole, so that the first supporting rod 102 is horizontally relative to the second supporting rod 103 Move, after adjusting the position, connect and fix with bolts, the motor frame 101 is positioned on the first support rod 102, can move in the vertical direction along the first support rod 102, after adjusting the position, three on the motor frame 101 The split fixing ring 104 is used to fix the vertical position of the motor frame 101 to ensure that the motor frame 101 is horizontal.

Please refer to FIG. 2 and FIG. 4 , the main function of the second aligning module 2 is to adjust the horizontal position of the sample holding module 4 on the table through the two-dimensional workbench 201 , so that the bearing ring is coaxial with the sample rotating module 3 . The two-dimensional workbench 201 moves in the first direction and the second direction by rotating the first direction knob 204 and the second direction knob 205. The two directions are perpendicular to each other. There are scales on the two knobs to determine the sample holding module 4, there are multiple upper positioning holes 202 on the surface of the two-dimensional workbench 201 for fixing the sample holding module 4, and there are four lower positioning holes 203 below the two-dimensional workbench 201 for placing the two-dimensional workbench 201 Fix on the rotating disc 301 of the sample rotating module 3 with screws, so that the two-dimensional worktable 201 rotates following the sample rotating module 3, thereby driving the bearing ring on the sample holding module 4 to rotate, and the rotation is realized through the rotating disc switch 302 The disk 301 stops or rotates. By rotating the disk speed control knob 303 to achieve different speeds of the rotating disk 301, set a lower speed to reduce the problem of uneven force on the surface of the bearing ring caused by the processing error of the polishing head, and to equalize the error , to ensure high surface accuracy of the bearing ring.

Please refer to Fig. 5 and Fig. 6, the main function of the sample clamping module 4 is to provide targeted bearing inner and outer ring clamps, and to accommodate polishing fluid; the bearing ring clamps include bearing outer ring clamps 401, bearing inner ring clamps 407, They are respectively used to fix the bearing outer ring 404 and the bearing inner ring 408. The polishing liquid pool 402 is used to accommodate the polishing liquid and fix the bearing ring fixture. The polishing liquid pool 402 is fixed on the pad 403, and the pad 403 passes through two One short pin 405 and two long pins 406 are fixed on the second aligning module 2, and move and rotate following the second aligning module 2. After polishing, remove the positioning pins, take out the spacer 403, and move the sample downward Clamp the module 4, separate the bearing ring from the polishing head, and take out the bearing ring.

The bottom of the bearing outer ring fixture 401 is a disc base with the same outer diameter as the inner diameter of the polishing liquid pool 402, and a coaxial cylinder is formed above the disc base. There is a coaxial stepped hole inside the cylinder, and the upper part of the stepped hole is The diameter is slightly larger than the outer diameter of the bearing outer ring 404, which is convenient for the bearing outer ring 404 to be put in. There are four threaded holes on the upper part of the stepped hole, and the bearing outer ring 404 is fixed by screwing to prevent it from rotating. The inner diameter of the lower part of the stepped hole is smaller than that of the bearing outer ring 404. diameter, greater than the inner diameter of the bearing outer ring 404, so that the bearing outer ring 404 is maintained at a specific height, and at the same time it is convenient to polish the entire inner surface of the bearing outer ring 404, and four gaps are evenly arranged around the cylinder to facilitate the entry of polishing liquid; the bearing inner ring fixture 407 The bottom is a disc base with the same outer diameter as the inner diameter of the polishing liquid pool 402, and a stepped shaft coaxial with it is above the disc base. Installed on the upper part of the stepped shaft through interference fit, the diameter of the lower part of the stepped shaft is larger than the inner diameter of the inner ring 408 of the bearing, and smaller than the outer diameter of the inner ring 408 of the bearing, so that the inner ring 408 of the bearing can be kept at a specific height, and at the same time, it is convenient for the polishing head to polish the inside of the bearing The entire outer surface of ferrule 408 .

Please refer to Fig. 7 and Fig. 8, the main function of polishing module 5 is to provide bearing inner and outer ring polishing heads in a targeted manner, and to control the rotation of the polishing heads to polish the bearing rings; the polishing head is composed of a substrate and a polishing pad 504. Composition, the polishing pad 504 adheres to the surface of the substrate, the substrate and the polishing pad 504 are made of flexible materials, comprehensively considering the elasticity and matching, the substrate material is silica gel at 70 degrees, and the polishing pad 504 is made of porous polyurethane.

The substrate of the bearing outer ring polishing head 503 is a cylinder, and the upper part has a cylindrical hole with the same inner diameter as the outer diameter of the motor shaft, and has a keyway. After the polishing pad 504 is adhered to the outer surface of the cylinder, the outer diameter is the same as the inner diameter of the bearing outer ring 404; The substrate of the bearing inner ring polishing head 505 is a cylinder, the upper part has a cylindrical hole with the same inner diameter as the motor shaft outer diameter, and has a keyway, and the lower part has a cylindrical hole. After the inner surface of the cylindrical hole adheres the polishing pad 504, the inner diameter is the same as The outer diameters of the bearing inner rings 408 are the same.

The motor 501 is fixed on the center of the motor frame 101, and the polishing head is connected on the shaft of the motor 501 by a key. By controlling the motor controller 502, the motor 501 can realize different speeds, and drive the polishing head to rotate. Under the joint action of 504 and chemical mechanical polishing fluid, the bearing ring is polished.

Please refer to Figure 9 and Figure 10, a bearing ring contact type ultra-precision chemical mechanical polishing device in Embodiment 1 is used for polishing, and the polishing method includes the following steps:

S1. Fix the second alignment module 2 on the sample rotation module 3, install the bearing ring on the sample holding module 4, fix the sample holding module 4 on the second alignment module 2, and install in sequence The first centering module 1 and the polishing module 5 adjust the position through the first centering module 1 and the second centering module 2, so that the polishing head, the bearing ring and the sample rotation module 3 are coaxial, while ensuring that the polishing head and the sample rotating module 3 are coaxial. Full contact of bearing rings;

S2, configure the chemical mechanical polishing liquid, in view of the bearing ring material is 9Cr18Mo stainless bearing steel, the polishing liquid includes 2wt% colloidal silicon dioxide, 1 wt% hydrogen peroxide, the remainder is water, the pH value is 4, stir evenly, Pour the polishing liquid into the polishing liquid pool 402, wherein 2 wt% of colloidal silicon dioxide can provide sufficient mechanical action, and 1 wt% of hydrogen peroxide can generate a uniform layer of iron-chromium oxide on the surface of the bearing steel film, and has a passivation effect, which helps to achieve nano-scale surface roughness, and a pH value of 4 can take into account both material removal rate and surface roughness;

S3. Set the polishing process parameters, wherein the ambient temperature is set to 22°C~23°C, and the speed of the polishing module 5 is set to 280 r/min. This speed can not only achieve high-speed polishing, but also ensure that the polishing liquid will not splash out of the polishing liquid In the pool 402, the speed of the sample rotation module 3 is set to 10 r/min. This speed can reduce the problem of uneven force on the surface of the bearing ring caused by the processing error of the polishing head, and the homogenization error. After setting the parameters, perform polishing;

S4. After the polishing is completed, the bearing ring is removed, and the surface quality after polishing is detected by a three-dimensional topography instrument.

The photos of bearing rings before and after polishing are shown in Figure 11 and Figure 13. By comparison, it is found that the surfaces of the inner and outer rings of the bearing can only reflect blurred reflections before polishing, but can reflect clear reflections after polishing, and the surface quality is obviously improved. The test results of the three-dimensional profiler after polishing are shown in Figure 12, in which the left picture shows the large diameter of the bearing inner ring 408, the surface roughness S _a is 1.02 nm, and the right picture shows the small diameter of the bearing inner ring 408, the surface roughness The degree S _a is 1.32 nm.

In summary, the present invention discloses a contact type ultra-precision chemical mechanical polishing device and method for bearing rings. The present invention specifically designs the polishing heads and fixtures for the inner and outer rings of bearings; Minimize the error, realize the uniform polishing of the surface of the bearing ring; design the polishing liquid for the stainless bearing steel, so that the surface roughness of the bearing ring is close to 1 nm, compared with the invention patent "ultra-precision flexible chemical mechanical polishing device and method for the core component of the miniature bearing" "The test results show that the surface roughness is reduced by an order of magnitude, and the ultra-precision machining of the bearing ring is realized.

While this specification describes examples of embodiments of the invention, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Those skilled in the art will appreciate that the embodiments described here are to help readers understand the principles of the present invention, and it should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical revelations disclosed in the present invention without departing from the essence of the present invention, and these modifications and combinations are still within the protection scope of the present invention.

Claims (9)

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.

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