Although both linear guides and linear round rails (also known as linear circular guides) are linear motion guide components, they differ significantly in their structural design, performance characteristics, and applicable scenarios.
Structural Differences
Linear guides utilize a combined "rail + slider" structure. The rail is a long, rectangular or square metal member with precision rolling grooves machined into its surface (mostly for ball or roller tracks). The slider houses recirculating rolling elements (balls or rollers) and is connected to the moving part via flanges or threads, creating a rigid fit.
Linear circular rails consist of an "optical shaft (circular guide) + sleeve (slider)." The optical shaft is a high-precision cylindrical metal rod with a hardened surface treatment (such as chrome plating). The sleeve typically contains a sliding bearing (copper or composite material) or a rolling bearing (linear bearing). By sliding onto the optical shaft, the sleeve achieves linear motion, resulting in a simpler structure.
Guiding Accuracy and Load Capacity
Guiding Accuracy:
Linear guides, due to the rigid multi-directional constraint between the rail and slider (typically rated static moments in four directions), effectively suppress deflection and wobble of moving parts. Their positioning accuracy can reach ±0.01mm/m, with a repeatability of ≤0.005mm.
The guiding accuracy of circular rails is affected by the parallelism of the optical axis and the clearance between the shaft and sleeve. Single-axis guidance is prone to radial offset, with positioning accuracy generally at ±0.05mm/m, making it suitable for applications with low precision requirements.
Load Capacity:
Linear guides, through line contact or surface contact (roller-type) between rolling elements and the rail, can withstand multi-directional loads such as radial, axial, and overturning moments. Their dynamic load ratings can reach several tons (e.g., heavy-duty guides).
Circular rails primarily withstand radial loads, have weak axial load capacity, and exhibit poor torsional resistance with a single optical axis. Therefore, two parallel optical axes are typically used to improve stability.
Motion Characteristics and Friction Coefficient
Friction Coefficient:
Linear guides (rolling-type) have an extremely low friction coefficient (0.001-0.002), low starting resistance, and smooth motion, making them suitable for high-speed reciprocating motion (speeds exceeding 3m/s).
Among linear circular guides, sliding sleeve types have a higher friction coefficient (0.05-0.1), while rolling bearing types have a coefficient of approximately 0.002-0.005. However, they are prone to vibration due to centrifugal force during high-speed operation.
Operational Smoothness:
The rolling element recirculation structure of linear guides reduces vibration and noise, enabling accelerations of up to 50m/s².
If the clearance of linear circular guides is not properly controlled, they are prone to "creeping" and exhibit poor stability during high-speed operation.
Contact Information
Address
Lishui City Yongrun Precision Machinery Co., Ltd., No.95, Tongji Street, Liandu District, Lishui, Zhejiang, China 323000
Wechat/Whatsapp/Mob
+86 18042376316
Website
https://www.cnballscrew.com/