Composite precise grinding device and method for bearing outer ring channel

Abstract

The invention relates to a composite precise grinding device and method for a bearing outer ring channel, and belongs to the technical field of bearing machining, and the device comprises a chuck body used for fixing a bearing outer ring and driving the bearing outer ring to rotate; a spherical grinding head capable of moving in the radial direction is arranged on the chuck body and used for grinding a bearing outer ring channel. The oilstone frame rod is driven by a motor and used for supporting the oilstone to make contact with the outer circle of the bearing outer ring so as to conduct swing type superfinishing on an outer ring channel. During use, after a workpiece is clamped and positioned, a plurality of procedures from coarse grinding to fine grinding are sequentially and independently carried out by adopting different spherical grinding heads respectively; and then the oilstone frame rod is driven to do small-angle reciprocating rotation, and the oilstone is adopted for swing type superfinishing. Grinding and superfinishing of the bearing ring can be completed on the same equipment, the tool setting link is reduced, the precision is improved, and the production efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of bearing processing technology, and particularly relates to a composite precision grinding device and method for bearing outer ring grooves. Background Technology

[0002] High-performance bearings, as core components of the machinery industry, directly impact the precision, efficiency, lifespan, and reliability of main equipment. With the rapid development of high-end equipment manufacturing, aerospace, precision instruments, and new energy vehicles, traditional metal bearings are increasingly unable to meet application requirements under extreme conditions (such as high temperature, strong corrosion, lack of lubrication, and large temperature differences). Ceramic materials, especially high-performance engineering ceramics such as silicon nitride (Si3N4) and zirconium oxide (ZrO2), have become ideal materials for manufacturing high-performance bearings due to their excellent properties, including low density, high hardness, good wear resistance, low coefficient of thermal expansion, corrosion resistance, and self-lubrication. Ceramic bearings are gradually becoming key components in the upgrading and replacement of advanced equipment.

[0003] The manufacturing process of ceramic bearings is far more complex than that of metal bearings. Its main processes include ceramic powder preparation, molding, sintering, and grinding. The sintered ceramic bearing ring blanks have low precision and poor surface quality, requiring precision grinding and ultra-precision grinding to achieve extremely high dimensional accuracy, geometric accuracy, and surface roughness requirements. Ultra-precision machining, as the final finishing process in bearing ring production, aims to remove surface defects such as altered layers and microcracks generated during previous grinding processes, reduce surface roughness, and correct micro-geometry, thereby obtaining an ideal working surface. This plays a decisive role in the bearing's vibration, noise, service life, and reliability.

[0004] Currently, the industry largely uses and improves upon traditional metal bearing processes and equipment for machining the outer raceways of ceramic bearings. However, traditional machining equipment exhibits several limitations when applied to ceramic outer raceways: First, there is a significant contradiction between machining efficiency and precision. To avoid chipping of brittle materials, conservative process parameters such as low pressure and low oscillation frequency are often used, resulting in extremely low material removal rates and low production efficiency. Traditional ultra-precision equipment typically uses external cylindrical ultra-precision machines, but their disadvantage lies in the potential instability of the raceway rotation when the speed increases, thus preventing the achievement of relatively high speeds and affecting machining speed and precision. Furthermore, improper parameter settings can easily cause micro-cracks and other damage on the surface / subsurface, further reducing yield and operational reliability. Second, there is insufficient adaptability and stability. Traditional equipment uses a single oilstone oscillation trajectory (mostly sinusoidal oscillation), making it difficult to intelligently adjust according to the curvature of the ceramic outer raceway and the initial surface shape error after sintering. This prevents optimal contour grinding and easily leads to poor profile accuracy.

[0005] Furthermore, the machining of ceramic bearing rings currently suffers from slow production due to the inherent material properties of ceramics, resulting in long processing times and numerous steps. Additionally, the numerous steps necessitate frequent equipment changes to complete different steps during bearing ring machining. This requires tool setting after each equipment change, which not only restricts processing speed but also significantly impacts workpiece clamping accuracy, leading to a decline in machining quality.

[0006] Therefore, existing ultra-precision equipment struggles to efficiently, accurately, and consistently complete the raceway grinding and ultra-precision machining of ceramic bearing outer rings. This has become a technological bottleneck restricting the large-scale industrial application of high-performance ceramic bearings. Developing a new machining device specifically designed for ceramic bearing outer rings that overcomes these shortcomings is of significant engineering application value and urgency for improving the performance, reliability, and independent controllability of my country's high-end bearings. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a composite precision grinding device and method for bearing outer ring grooves, which can complete the grinding and ultra-precision grinding of bearing outer ring grooves on the same equipment.

[0008] A composite precision grinding apparatus for bearing outer ring grooves, comprising:

[0009] The chuck body is used to fix the outer ring of the bearing and drive its rotation.

[0010] The chuck body is equipped with a radially movable spherical grinding head for grinding the outer ring groove of the bearing;

[0011] The oilstone support rod, driven by a motor, is used to support the outer circle of the oilstone contact bearing so as to perform oscillating ultra-precision on the outer ring groove.

[0012] The chuck body is a three-jaw chuck.

[0013] The multiple spherical grinding heads employ different grit sizes and are each driven by a separate motor to achieve different grinding processes on the grooves.

[0014] There are three spherical grinding heads, used for rough grinding, semi-finishing, and fine grinding respectively.

[0015] The chuck body has multiple connecting slots evenly distributed along its circumference. The spherical grinding head is installed in the connecting slot and is driven by a motor, enabling it to move radially along the connecting slot along the chuck body.

[0016] The motor for driving the spherical grinding head is mounted on the chuck body via a lead screw mechanism, and is driven by the lead screw mechanism to move along the connecting slot.

[0017] A pressure sensor is installed on the spherical grinding head.

[0018] The motor driving the oilstone support rod is movably connected to the base, and its movement direction is parallel to the rotation center of the chuck body, so as to move closer to or further away from the outer ring of the bearing on the chuck body.

[0019] The oilstone support rod is a concave connecting rod.

[0020] A composite precision grinding method for bearing outer ring grooves, employing the aforementioned composite precision grinding apparatus for bearing outer ring grooves, specifically includes:

[0021] Workpiece clamping and positioning;

[0022] Different spherical grinding heads are used to perform multiple processes from coarse grinding to fine grinding in sequence;

[0023] The drive oilstone support rod rotates back and forth at a small angle, and the oilstone is used for oscillating ultra-precision.

[0024] By employing the above technical solution, the present invention has at least the following beneficial effects:

[0025] 1. The composite precision grinding device and method for bearing outer ring grooves provided by the present invention can realize the grinding and ultra-precision grinding of bearing rings on the same equipment, reduce tool setting, improve accuracy, and improve production efficiency.

[0026] 2. In the composite precision grinding device for bearing outer ring groove provided by the present invention, a three-jaw chuck is used to fix and rotate the bearing outer ring, and the inner groove of the bearing outer ring is ground using a spherical grinding head; the three spherical grinding heads can use different grit sizes, and the three drive motors corresponding to the three spherical grinding heads can be set to different speeds to continuously complete multiple processes, thereby improving surface quality and production efficiency.

[0027] 3. The present invention adopts an oscillating inner ring ultra-precision, which can make the wear of the oilstone more uniform and improve the surface processing quality of the groove.

[0028] 4. Without changing the clamping method of existing machine tools, this invention can realize rough grinding, semi-fine grinding, fine grinding, and ultra-fine grinding processes of ceramic bearing raceway. Attached Figure Description

[0029] Figure 1 A schematic diagram of a composite precision grinding device for the outer ring groove of a bearing provided by the present invention;

[0030] in:

[0031] 1-Grinding head drive motor, 2-Ceramic bearing outer ring, 3-Chuck body, 4-Sliding base, 5-Universal joint, 6-Oscillating motor of oilstone support rod, 7-Oscillating stone support rod, 8-Spherical grinding head, 9-Connecting shaft, 10-Oscillating stone support. Detailed Implementation

[0032] To better explain and facilitate understanding of the present invention, the technical solution and effects of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] like Figure 1 As shown, a composite precision grinding device for the outer ring groove of a bearing includes a chuck body 3, which is a three-jaw chuck used to fix the outer ring of the bearing and drive its rotation. Three connecting slots are evenly distributed circumferentially on the chuck body 3 for fixing the grinding head drive motor 1 and connecting the connecting shaft 9. The connecting shaft 9 passes through the connecting slots, with one end connected to the output end of the grinding head drive motor 1 and the other end connected to a spherical grinding head 8. The grinding head drive motor 1 drives the spherical grinding head 8 to rotate. The three spherical grinding heads 8 contact the bearing ring groove to perform grinding.

[0034] Furthermore, the three spherical grinding heads 8 employ different grit sizes and are driven by three independent grinding head drive motors 1 to complete the rough grinding to fine grinding of the grooves. They can also perform rough grinding, semi-fine grinding, and fine grinding of the grooves of the ceramic bearing outer ring 2 on the same equipment. Specifically, in this embodiment, the three spherical grinding heads 8 are a rough grinding head, a semi-fine grinding head, and a fine grinding head. The rough grinding head is used to remove most of the excess material from the ceramic bearing outer ring 2 blank and correct the initial surface shape error after sintering; the semi-fine grinding head is used to refine the surface roughness of the grooves and correct the micro-cracks generated by rough grinding; the fine grinding head further improves the groove accuracy, laying the foundation for ultra-precision processes.

[0035] Furthermore, the grinding head drive motor 1 is mounted on the chuck body 3 via a lead screw mechanism. The grinding head drive motor 1 is driven by the lead screw mechanism to move along the connecting groove. Specifically, the lead screw mechanism is fixed to the chuck body 3, and the grinding head drive motor 1 is threadedly connected to the lead screw of the lead screw mechanism via a slider. The grinding head drive motor 1 drives the lead screw to rotate, thereby causing the grinding head drive motor 1 to move along the connecting groove, thus realizing the adjustment of the radial position of the grinding head drive motor 1. In order to realize the adjustment of the groove pressure of the outer ring 2 of the ceramic bearing and multi-process grinding, a pressure sensor is provided on the spherical grinding head 8.

[0036] The device also includes an oilstone holder oscillating motor 6. An oilstone holder 7 is connected to the output end of the oilstone holder oscillating motor 6 via a universal joint 5. The oilstone holder 7 is driven by the oilstone holder oscillating motor 6 to perform small-angle reciprocating rotation, achieving small-angle reciprocating oscillation. In this embodiment, the oscillation angle of the oilstone holder 7 is 20°. The universal joint 5 is a cross universal joint, allowing the oilstone holder 7 to move freely. Furthermore, an oilstone holder 10 is connected to the end of the oilstone holder 7. The oilstone holder 10 is equipped with an oilstone to support the oilstone in contact with the outer circle of the ceramic bearing outer ring 2, for oscillating grinding of the grooves of the ceramic bearing outer ring 2.

[0037] The honing stone support rod 7 is a concave connecting rod, avoiding the interference problem between the rod body and the outer circle of the ceramic bearing outer ring 2 caused by the thickness of the rod body in the traditional straight rod structure. This eliminates the need to increase the distance between the honing stone support rod 7 and the ceramic bearing outer ring 2, ensuring the honing stone can fit closer to the groove surface. Simultaneously, compared to a straight rod, the concave connecting rod exhibits a more uniform stress distribution at the same swing angle, reducing rod vibration caused by small-angle swings and preventing intermittent detachment between the honing stone and the groove, thus ensuring stable ultra-precision pressure. Furthermore, the concave area of ​​the connecting rod avoids the chuck body 3, allowing for flexible swinging of the honing stone support rod 7 without adjusting the installation positions of other core components of the existing machine tool, thus meeting the design premise of not changing the existing machine tool clamping method.

[0038] Furthermore, the concaveness of the concave connecting rod can be preset according to the outer diameter of the outer ring of the target bearing and the position of the groove, so that when the oilstone support rod 7 driven by the swing motor 6 and the universal joint 5 swings, the oilstone always maintains the contact angle with the groove generatrix, reducing the local suspension or excessive compression of the oilstone caused by the rod structure, and improving the uniformity of the groove surface after ultra-precision.

[0039] Furthermore, the swing motor 6 of the oilstone support rod is slidably connected to the sliding base 4 via a slider. The slider is located at the bottom of the swing motor 6 and is slidably connected in the sliding groove of the sliding base 4. The sliding direction of the slider along the sliding groove is parallel to the rotation center of the chuck body 3, thereby realizing the movement of the swing motor 6 of the oilstone support rod 7 to move closer to or away from the outer ring 2 of the ceramic bearing on the chuck body 3.

[0040] In use, the chuck body 3 completes the circumferential fixing and rotation of the outer ring 2 of the ceramic bearing; the grinding head drive motor 1 rotates, driving the spherical grinding head 8 to contact the groove of the outer ring 2 of the ceramic bearing to complete the grinding process. The oilstone holder swing motor 6 reciprocates at a small angle, transmitting power to the oilstone holder 10 through the universal joint 5 and the oilstone holder rod 7, causing the oilstone on the oilstone holder 10 to swing on the groove of the outer ring 2 of the ceramic bearing, completing the ultra-precision grinding of the groove of the outer ring 2 of the ceramic bearing. Specifically, the method of performing composite precision grinding using the above-mentioned composite precision grinding device for the outer ring groove of the bearing includes:

[0041] Workpiece clamping and positioning: Clamp the outer ring 2 of the ceramic bearing on the chuck body 3 and fix the outer ring 2 of the ceramic bearing circumferentially to ensure that the axis of the outer ring 2 of the ceramic bearing is coaxial with the axis of the chuck body 3.

[0042] Rough grinding process:

[0043] Start the grinding head drive motor 1 corresponding to the coarse grinding ball grinding head, and drive the coarse grinding ball grinding head radially through the lead screw mechanism until the pressure sensor displays the preset pressure value of the contact pressure, drive the outer ring 2 of the ceramic bearing to rotate, and drive the grinding head drive motor 1 to rotate according to the preset speed to remove the sintering allowance of the groove of the outer ring 2 of the ceramic bearing.

[0044] After rough grinding is completed, the lead screw mechanism drives the rough grinding ball head to retract to a safe position, and the groove size is checked to confirm that the allowance removal meets the requirements.

[0045] Semi-finishing process:

[0046] Start the grinding head drive motor 1 corresponding to the semi-fine grinding spherical grinding head, and drive the semi-fine grinding spherical grinding head radially through the lead screw mechanism until the pressure sensor displays the preset pressure value of the contact pressure, drive the outer ring 2 of the ceramic bearing to rotate, and drive the grinding head drive motor 1 to rotate according to the preset speed, thereby reducing the surface roughness and correcting the roundness error caused by rough grinding.

[0047] After rough grinding is completed, the lead screw mechanism drives the semi-fine grinding spherical grinding head back to a safe position.

[0048] Fine grinding process:

[0049] Start the grinding head drive motor 1 corresponding to the precision grinding spherical grinding head, and drive the precision grinding spherical grinding head radially through the lead screw mechanism until the pressure sensor displays the preset pressure value of the contact pressure, drive the outer ring 2 of the ceramic bearing to rotate, and drive the grinding head drive motor 1 to rotate according to the preset speed, and process to meet the technical requirements.

[0050] After rough grinding is completed, the lead screw mechanism drives the fine grinding ball head to retract to a safe position.

[0051] Ultra-precision process:

[0052] Adjust the position of the oilstone support rod swing motor 6 on the sliding base 4 to adjust the position of the oilstone support rod 7 so that the oilstone fits the curved surface of the channel; then start the oilstone support rod swing motor 6, and at the same time drive the outer ring 2 of the ceramic bearing to rotate, and perform ultra-precision under the preset pressure.

[0053] Process completion and workpiece unloading:

[0054] After all the above processes are completed, the spherical grinding head 8 and the oilstone are returned to the safe position, the chuck body 3 is released, the processed ceramic bearing outer ring 2 is removed, and the next workpiece is clamped and processed.

Claims

1. A composite precision grinding device for the outer ring groove of a bearing, characterized in that, include: The chuck body is used to fix the outer ring of the bearing and drive its rotation. The chuck body is equipped with a radially movable spherical grinding head for grinding the outer ring groove of the bearing; The oilstone support rod, driven by a motor, is used to support the outer circle of the oilstone contact bearing so as to perform oscillating ultra-precision on the outer ring groove.

2. The composite precision grinding device for bearing outer ring grooves according to claim 1, characterized in that: The chuck body is a three-jaw chuck.

3. The composite precision grinding device for bearing outer ring grooves according to claim 1, characterized in that: The multiple spherical grinding heads employ different grit sizes and are each driven by a separate motor to achieve different grinding processes on the grooves.

4. The composite precision grinding device for bearing outer ring grooves according to claim 3, characterized in that: There are three spherical grinding heads, used for rough grinding, semi-finishing, and fine grinding respectively.

5. The composite precision grinding device for bearing outer ring grooves according to claim 1, characterized in that: The chuck body has multiple connecting slots evenly distributed along its circumference. The spherical grinding head is installed in the connecting slot and is driven by a motor, enabling it to move radially along the connecting slot along the chuck body.

6. The composite precision grinding device for bearing outer ring grooves according to claim 5, characterized in that: The motor for driving the spherical grinding head is mounted on the chuck body via a lead screw mechanism, and is driven by the lead screw mechanism to move along the connecting slot.

7. The composite precision grinding device for bearing outer ring grooves according to claim 1, characterized in that: A pressure sensor is installed on the spherical grinding head.

8. The composite precision grinding device for bearing outer ring grooves according to claim 1, characterized in that: The motor driving the oilstone support rod is movably connected to the base, and the direction of movement is parallel to the rotation center of the chuck body, so as to move closer to or further away from the outer ring of the bearing on the chuck body.

9. The composite precision grinding device for bearing outer ring grooves according to claim 1, characterized in that: The oilstone support rod is a concave connecting rod.

10. A composite precision grinding method for bearing outer ring grooves, employing the composite precision grinding apparatus for bearing outer ring grooves as described in any one of claims 1 to 9, characterized in that, Specifically, it includes: Workpiece clamping and positioning; Different spherical grinding heads are used to perform multiple processes from coarse grinding to fine grinding in sequence; The drive arm of the oilstone rotates back and forth at a small angle, and the oilstone is used for oscillating ultra-precision.

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