JP-2026076034-A - Rolling guide device

Abstract

[Problem] To provide a rolling guide device that can appropriately set the number and material of the spacer balls to be inserted, thereby suppressing competition between rolling elements in the unloaded rolling path and achieving excellent operability. [Solution] The linear guide device (rolling guide device) 10 includes a guide rail 1, a slider 2 assembled to the guide rail 1, and a plurality of rolling elements that are rotatably filled into rolling element tracks 23a, 23b, which consist of loaded rolling elements 22a, 22b and unloaded rolling elements 21a, 21b. The plurality of rolling elements are composed of a plurality of steel balls 6 and a plurality of spacer balls 16 that are smaller than the loaded balls and have elasticity, and there is always at least one spacer ball in each unloaded rolling element, and the total spring constant of all spacer balls present in each unloaded rolling element is 3.4 (N/mm) or less. [Selection Diagram] Figure 4

Inventors

• 大久保 努

Assignees

• 日本精工株式会社

Dates

Publication Date

20260511

Application Date

20241023

Claims (5)

1. A first member having a first raceway groove on its side, A second member is assembled to the first member and has a second raceway groove facing the first raceway groove, The rolling element track comprises a load-loaded rolling path formed by the first and second raceway grooves, and an unloaded rolling path provided on the second member that connects one end and the other end of the load-loaded rolling path, and a plurality of rolling elements that are filled in such a manner that they can roll freely. A rolling guide device in which one of the first member and the second member moves relative to the other as the rolling element rolls, The aforementioned plurality of rolling elements are composed of a plurality of load balls and a plurality of spacer balls that are smaller than the load balls and have elasticity. At least one of the spacer balls is always present in the unloaded rolling path. A rolling guide device in which the total spring constant of all spacer balls present in the unloaded rolling path is 3.4 (N/mm) or less.
2. The rolling guide device according to claim 1, wherein the spacer ball is made of one selected from synthetic rubber, resin, and thermoplastic elastomer.
3. The rolling guide device according to claim 1, wherein the diameter of the spacer ball is 90% or more of the diameter of the load ball.
4. The rolling guide device according to claim 1, wherein the number of spacer balls is less than the number of load balls.
5. The rolling guide device according to claim 1, wherein the plurality of spacer balls are arranged at approximately equal intervals between the load balls.

Description

This invention relates to a rolling guide device used in measuring machines and machine tools, etc., for guiding a reciprocating object in its direction of movement. A linear guide, as a rolling guide device, generally comprises a guide rail with rail-side rolling grooves on its left and right sides, a slider with slider-side rolling grooves positioned opposite the rail-side rolling grooves on the guide rail, and numerous rolling elements that fill a load rolling path (formed by the rail-side and slider-side rolling grooves) and a rolling element return path (provided inside the slider), allowing them to roll along these paths. End caps are fitted to both axial ends of the slider, and direction-changing paths for reversing the direction of the rolling elements are formed within the end caps. The rolling elements then roll along the unloaded rolling path (formed by the rolling element return path and direction-changing path) and the load rolling path, causing the slider to move relative to the guide rail in the axial direction. After reversing direction within the end caps, the rolling elements return to their original positions through the rolling element return paths formed inside the slider. In such linear guides, within the load-driven path, the directions of movement of adjacent rolling element surfaces are opposite to each other. As a result, frictional forces generated at the contact points between rolling elements can hinder the smooth operation of the slider. Furthermore, the unloaded rolling path is formed to be larger than the diameter of the rolling element, and the rolling elements in the unloaded rolling path move by being pushed by the rolling elements in the loaded rolling path. Similar to the loaded rolling path, this causes competition between the rolling elements, reducing the operability of the slider. Therefore, in order to improve the operability of the rolling guide device, a device is disclosed in which spacers of various materials are placed between adjacent rolling elements. For example, Patent Document 1 describes a rolling guide device in which a solid lubricating film is formed over at least a portion of the infinite circulation path (rolling path), and spacer balls, which are softer than the rolling elements and have a diameter less than or equal to the diameter of the rolling elements, are installed between the rolling elements. Furthermore, Patent Document 2 proposes a linear rolling guide unit in which the rolling elements are composed of ceramic balls and, for example, urethane balls. In this linear rolling guide unit, it is preferable to arrange the ceramic balls and urethane balls alternately to prevent damage caused by friction between the ceramic balls. Also, because the rolling elements are lighter than steel rolling elements, responsiveness to high-speed motion is improved, interference noise is reduced, and overall noise is decreased. Furthermore, Patent Document 3 discloses a rolling guide device in which the rolling elements consist of a plurality of first rolling elements and a plurality of second rolling elements (elastic balls) made of an elastic material, and at least one second rolling element is always positioned in the circulation path (unloaded rolling path). Japanese Patent Publication No. 2008-232267Japanese Patent Application Publication No. 8-61364International Publication No. 2016/190147 This is a perspective view showing a rolling guide device according to an embodiment of the present invention, with a portion of the rolling element's path partially cut away.This is a schematic cross-sectional view of the rolling guide device shown in Figure 1.This diagram schematically shows the III-III cross section in Figure 2, with (a) representing the position before movement and (b) representing the position after movement.This is a schematic diagram illustrating the arrangement of two elastic spacer balls in a rolling guide device.This is a schematic diagram illustrating an alternative arrangement of two elastic spacer balls in a rolling guide device.This is a schematic diagram illustrating the arrangement of three elastic spacer balls in a rolling guide device.This is a schematic diagram illustrating the arrangement of six elastic spacer balls in a rolling guide device.This graph shows the kinetic friction force generated when the slider is moved back and forth in Test Example 1.This graph shows the kinetic friction force generated when the slider is moved back and forth in Test Example 2.This graph shows the kinetic friction force generated when the slider is moved back and forth in Test Example 3.This graph shows the kinetic friction force generated when the slider is moved back and forth in Test Example 4.This graph shows the kinetic friction force generated when the slider is moved back and forth in Test Example 5.This graph shows the relationship between load and deformation of the elastic spacer ball for each type of elastic spacer ball.This graph shows t