Zero-error roundness centerless grinding forming device capable of real-time size measurement and control

Abstract

This invention discloses a zero-error roundness centerless grinding device with online closed-loop dimensional measurement and control, belonging to the field of precision bearing grinding technology. Addressing the industry pain points of traditional grinding machines worldwide—namely, inherent roundness errors due to eccentricity and uneven loading, lack of end-to-end online precision control, and poor batch consistency—this invention employs a double-symmetrical rigid fulcrum to permanently lock the workpiece center. Combined with a power mechanism driving the workpiece to rotate concentrically, the grinding wheel performs symmetrical and balanced grinding around the circumference. Simultaneously, a high-precision dimensional measuring head collects workpiece parameters in real time and provides closed-loop dynamic compensation for grinding deviations. The device achieves alignment of the workpiece's rotation, geometry, grinding, and inspection centers, completely eliminating elliptical, angular, and radial runout errors at their structural root, achieving theoretically zero roundness and ultra-high precision machining. The equipment exhibits excellent rigidity, low operating vibration, and extremely high batch processing stability, filling the global gap in zero-error grinding technology for precision rotating parts under extreme working conditions.

Description

1. Technical Field:

[0001] This invention relates to the field of ultra-precision grinding technology for precision rotating parts, specifically to a zero-roundness error machining equipment for bearing rings and stainless steel motor spindles, which is particularly suitable for high-precision finishing of bearings without lubrication under extreme high and low temperature conditions. 2. Background Technology:

[0002] A comprehensive global novelty search was conducted, including PCT international patents, machine tool patents from various countries, process technologies from leading bearing companies such as SKF / NSK, and industry academic papers.

[0003] Existing globally used centerless grinding, hydrostatic cylindrical grinding, multi-wheel composite grinding, and bearing ultra-precision honing technologies all employ a single-sided floating centering + single-sided grinding force structure. The workpiece's rotation center and geometric center continuously offset each other, and the single-sided cutting force causes elastic deformation of the workpiece, inevitably producing inherent roundness errors such as ellipticity, edge roundness, and radial runout. The industry's precision limit is only 0.2 to 0.5 μm, making it impossible to achieve theoretically zero-error roundness machining.

[0004] Meanwhile, none of the existing grinding equipment has an integrated structure that combines double-symmetric rigid fixed-point locking of the center, full-circumference symmetrical balanced grinding, and real-time closed-loop measurement and control of dimensions throughout the grinding process. This makes it impossible to dynamically compensate for processing deviations, and the consistency of batch parts dimensions and long-term roundness stability cannot meet the stringent requirements of military-grade precision bearings.

[0005] No identical, equivalent, or similar principle and technical solutions were found globally. This invention fills a structural technology gap in the field of ultra-high precision roundness grinding worldwide. 3. Summary of the Invention:

[0006] Structural components (strictly corresponding to the symbols in the attached diagram)

[0007] 1- The ring-shaped workpiece being machined; 2- Rotary power drive mechanism; 3- Double symmetrical fixed limit fulcrum; 4- Circumferential grinding wheel; 5- High-precision online dimensional measuring head

[0008] Core technology solutions

[0009] Two sets of symmetrical fixed limiting support points 3 provide bidirectional radial rigid clamping constraints along the outer periphery of the workpiece, permanently locking the workpiece's center coordinates and completely limiting the workpiece's radial runout and center eccentricity offset, thus eliminating rotational reference drift from the root.

[0010] The rotating power mechanism 2 fits against the outer edge of the workpiece and smoothly drives the workpiece to rotate at a constant speed and coaxially around its own fixed geometric center, without slippage or additional eccentric torque throughout the entire process;

[0011] The grinding wheels are symmetrically arranged around the circumference of the workpiece, applying grinding force synchronously and uniformly around the entire circumference. The radial cutting forces on the circumference cancel each other out symmetrically, completely eliminating unilateral load-induced deformation.

[0012] The dimension measuring head 5 is closely attached to the outer circle of the workpiece, and collects the workpiece's outer diameter and roundness runout accuracy data in real time throughout the entire process. The closed-loop feedback controls the grinding wheel feed rate and dynamically and adaptively compensates for machining errors.

[0013] Ultimately, the four centers of the workpiece rotation center, geometric center, grinding center, and inspection center are permanently aligned, achieving ultra-high roundness machining of ring-shaped workpieces with theoretical zero error from the dual dimensions of mechanical structure and intelligent measurement and control.

[0014] Beneficial technical effects:

[0015] 1. The zero-error roundness centerless grinding forming device with real-time dimensional measurement and control specifically relates to a bearing ring and wheel grinding feed amount, which dynamically and adaptively compensates for machining errors;

[0016] Ultimately, the four centers of the workpiece's rotation center, geometric center, grinding center, and inspection center are permanently aligned. From the dual dimensions of mechanical structure and intelligent measurement and control, this achieves theoretically zero-error ultra-high roundness machining of ring-shaped workpieces. The beneficial technical effects overturn the century-old traditional floating centering grinding principle, with double rigid fulcrums locking and fixing the center, completely eliminating the original errors of clamping eccentricity and radial runout.

[0017] The circumferentially symmetrical and balanced grinding force ensures that the cutting stress is self-balanced and canceled out, resulting in no elastic deformation of the workpiece and a breakthrough in the global limit of roundness machining accuracy. The addition of full-process online closed-loop measurement and control of dimensions enables real-time detection and automatic compensation of deviations, ensuring that the consistency of the dimensions and roundness of batch parts is permanently stable and controllable. The machine has extremely high structural rigidity and minimal operating vibration, and can stably and accurately machine thin-walled bearing rings and stainless steel motor shafts with a length-to-diameter ratio.

[0018] It is perfectly adapted to bearings that do not require lubrication in extreme high and low temperature conditions ranging from -40℃ to 90℃. Its novelty, creativity, and practicality fully meet the standards for invention patent authorization. 4. Description of the attached diagram:

[0019] Figure 1 This is a schematic diagram of the overall principle and structure of the roundness machining machine with online dimensional measurement and control and zero error according to the present invention.

[0020] Figure label:

[0021] 1-The ring-shaped workpiece to be machined; 2-The rotating power mechanism; 3-The fixed limiting fulcrum; 4-The grinding wheel; 5-The dimensional measuring head 5. Detailed Implementation Methods

[0022] The workpiece 1, such as a ring bearing or motor shaft, is loaded into the machining station. The upper and lower double fixed limit fulcrums 3 radially and bidirectionally press and rigidly lock the geometric center position of the workpiece. The rotation power mechanism 2 is started, which drives the workpiece to rotate smoothly and uniformly around the fixed center. The grinding wheel 4 is fed synchronously, and the outer circle of the workpiece is symmetrically and synchronously ground. The dimension measuring head 5 collects the outer diameter and roundness parameters of the workpiece in real time throughout the process, and controls the grinding wheel feed amount in a closed loop to dynamically correct the machining deviation throughout the process. The workpiece has four centers aligned, the force is balanced, and the accuracy is calibrated in real time throughout the process. After the machining is completed, the workpiece is directly discharged to obtain a finished workpiece with theoretical zero roundness and ultra-high precision.

Claims

1. A zero-error centerless grinding forming device with real-time dimensional measurement and control, characterized in that: The system includes a ring-shaped workpiece (1), a rotating power mechanism (2), a double symmetrical fixed limiting mechanism (3), a surrounding grinding wheel (4), and an online dimension measuring head (5). The double fixed limiting mechanism (3) is arranged symmetrically around the circumference, providing bidirectional radial rigid constraint to the workpiece and permanently locking the center position of the workpiece. The rotating power mechanism (2) drives the workpiece to rotate smoothly coaxially around its fixed geometric center. The grinding wheel (4) is symmetrically distributed around the outer circumference of the workpiece, applying a balanced grinding load synchronously around the entire circumference. The dimension measuring head (5) is in contact with the outer edge of the workpiece, detecting the workpiece size and roundness data online in real time, and using closed-loop feedback to control the grinding wheel feed to compensate for machining errors.

2. The apparatus according to claim 1, characterized in that: The double fixed limiting fulcrum (3) is symmetrically distributed up and down, which completely restricts the radial runout and eccentric offset of the workpiece, so that the rotation center of the workpiece and its own geometric center are permanently coaxially coincident.

3. The apparatus according to claim 1, characterized in that: The surrounding grinding wheel (4) performs symmetrical synchronous grinding around the entire circumference. The circumferential cutting stress cancels out and balances each other, and there is no unilateral load extrusion deformation, so as to realize the precision machining of the outer circle of the ring workpiece with theoretical zero roundness error.

4. The apparatus according to claim 1, characterized in that: The dimension measuring head (5) is linked with the grinding wheel to form a closed-loop control system for the entire process, which is suitable for high-precision batch stable processing of bearings without lubrication and stainless steel motor shafts under extreme working conditions of -40℃~90℃.

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