What is the use of a roundness tester?

In precision manufacturing and quality inspection, the geometric accuracy of parts is crucial to product performance and reliability. As a core metrological instrument in this field, the roundness tester, with its superior performance and wide application, has become an indispensable tool for ensuring product quality. This article will delve into the salient features of a high-performance roundness tester and explain why it has become a cornerstone of modern industrial inspection.

Introduction

A roundness measuring instrument is a tool that uses a rotating axis to measure the roundness error of a workpiece. Roundness testers are available in two types: sensor-rotating and table-rotating. During measurement, the workpiece is mounted concentrically on a precision shaft system, which carries an inductive length sensor or table in precise circular motion. The entire system consists of a sensor, amplifier, filter, output device, and computer.

Table-rotating roundness testers typically have a high-precision rotating table on which the workpiece is placed and rotates. Simultaneously, a measuring sensor (usually inductive, capacitive, or photoelectric) moves perpendicular to the axis of rotation to measure the workpiece surface.

During the measurement process, the sensor collects data on the radial variation of the workpiece surface relative to the measurement reference (usually the axis of rotation). As the workpiece rotates, the sensor acquires a series of measurements at different angular positions. These measurements are processed and analyzed, and mathematical algorithms (such as the least squares method or the minimum area method) are used to calculate the workpiece's roundness error. Roundness error typically includes parameters such as roundness, cylindricity, concentricity, and coaxiality. Precise measurement and data analysis enable an accurate assessment of workpiece roundness.

Features

The Core of Measurement Accuracy

The heart of the roundness gauge lies in its spindle system. This instrument utilizes an ultra-high-precision spindle with impressive specifications: radial error is accurate to ±(0.025 + 5H/10.000) microns, and axial error is also controlled within ±(0.025 + 6H/10.000) microns. This ultra-precise accuracy means that even when measuring workpieces up to 400 mm in diameter, the spindle's rotational error can be strictly controlled to the micron level, establishing a near-perfect benchmark for measuring all geometric parameters. This inherently high stability ensures reliable data from every measurement, fundamentally eliminating misjudgments due to inherent equipment errors and providing an authoritative basis for quality control.

Powerful Versatility and Comprehensive Evaluation System

Modern industry is evaluating parts across increasingly diverse dimensions, and this roundness tester perfectly meets this challenge. It goes far beyond basic roundness measurement, boasting powerful geometric and positional tolerance testing capabilities, accurately assessing complex parameters such as coaxiality, concentricity, radial runout, perpendicularity, parallelism, flatness, and shaft bow. Furthermore, its surface waviness analysis, spectrum analysis, and wave height analysis capabilities enable engineers to delve from macroscopic geometry to microscopic surface texture, helping them analyze vibration sources and process defects during machining, achieving the leap from "detection" to "diagnosis."

Furthermore, the instrument incorporates four internationally recognized roundness assessment methods: the minimum area method, the least squares method, the minimum circumscribed circle method, and the maximum inscribed circle method. This multi-standard assessment system allows users to select the most appropriate algorithm based on the functional requirements and industry standards of each product, resulting in measurement results with greater engineering value and meeting comprehensive needs from research to production.

Robust Load Capacity and Flexible Adjustment Mechanism

To meet the demands of inspecting everything from small precision parts to medium-sized core components, this instrument features a robust mechanical structure. With a worktable load capacity of up to 50 kg and a rotation diameter of 400 mm, it can easily handle common industrial parts such as bearing rings, gears, and hydraulic valve bodies. The worktable is not only sturdy but also features precise adjustment capabilities, with an eccentricity adjustment range of ±2 mm and a horizontal adjustment range of ±1°. This allows for quick and precise alignment of workpieces, reducing tedious setup time and significantly improving inspection efficiency.

Combined with a highly rigid horizontal arm, it boasts a horizontal travel range of 150 mm and supports stepless electric speed regulation from 0.5-6 mm/s or manual fine adjustment, enabling the sensor to precisely locate any measured section of the workpiece. This flexible mechanical design easily handles measuring internal bores, external diameters, and end faces, demonstrating exceptional adaptability.

Our roundness tester integrates an ultra-high-precision spindle, a multifunctional measurement system, a robust and flexible mechanical platform, and high-resolution sensing technology. It is more than just a measuring instrument; it provides a complete geometric accuracy solution platform. It strictly adheres to professional standards such as SJBIT 10028-1999 and SJBIT 5996-1992. Its superior performance holds broad application prospects in a wide range of industries, including bearings, automotive, aerospace, and precision molds.

Investing in such a device establishes a solid technical barrier to product quality and is a key step in advancing manufacturing processes towards high-end, intelligent manufacturing.

Main Test Objects

1. Roundness, cylindricity, taper, diameter, coaxiality, concentricity, parallelism, perpendicularity, runout, straightness of cylindrical generatrix, end face straightness, runout of cylindrical end faces, flatness, angles, small arc segments, and diameter of various annular parts.

2. Roundness Assessment Methods (4): Minimum Area Method, Least Squares Method, Minimum Circumscribed Circle Method, and Maximum Inscribed Circle Method.

Working Principle

Sample Preparation: Place the object to be tested on the measuring table of the roundness tester.

Rotational Motion: Rotate the object on the measuring table using a motor or mechanical device.

Measuring Sensor: Uses a probe or measuring probe to scan along the object's surface and record surface deviation data.

Deviation Measurement: Measure surface deviation, typically using displacement data from the sensor or probe.

Roundness Analysis: Performs roundness analysis and calculations based on the measured deviation data to evaluate the object's roundness or contour shape.

Widely Used

1. Bearing Industry: Used to measure the roundness of bearing inner and outer rings to ensure bearing rotational accuracy and performance;

2. Machining: Used to measure the roundness of various mechanical parts, such as shafts, holes, and cylinders, to ensure part fit accuracy and mechanical performance;

3. Automotive Manufacturing: Used to measure the accuracy of key components such as engine cylinder blocks, wheel hubs, crankshafts, piston pins, and commutators;

4. Motor Industry: Used to measure the roundness of motor shafts and other parts;

5. Auto Parts Industry: Used to measure steel balls, needle rollers, rollers, oil pump nozzles, hydraulic components, pneumatic components, and textile machinery parts;

6. Motorcycle Parts Industry: Used to measure components such as motorcycle engines;

7. Hardware Industry: Used to measure tool handles;

8. Tool and Cutting Tool Manufacturing: Used to measure the roundness of cutting edges and other parts;

9. Mold Industry: Used to monitor the roundness of molds to ensure that finished products meet specifications;

10. Optical components: Ensure high-precision shapes of optical components;

11. Aerospace: Used in the manufacture and testing of various precision parts;

12. Electronics: Used to test precision components in electronic equipment;

13. Medical devices: For example, measuring key components of certain medical instruments;

14. Research institutes and universities: Used for related scientific research and teaching experiments;

15. Metrology institutions and corporate metrology rooms and workshops: Used to measure the roundness of various annular workpieces.

2025-10-21 16:50